Add "PreviousVersionInstalled" to SystemInformation (#4000)

## Fixes #3999 

Doc # [511](MicrosoftDocs/WindowsCommunityToolkitDocs#511)

Add "PreviousVersionInstalled" to SystemInformation to understand which version the app is updated from, to handle specific migration/changes.

## PR Type
Feature 

## What is the current behavior?
SystemInformation doesn't expose the PreviousVersionInstalled property


## What is the new behavior?
Expose "PreviousVersionInstalled" property


## PR Checklist

Please check if your PR fulfills the following requirements:

- [x] Tested code with current [supported SDKs](../readme.md#supported)
- [x] Pull Request has been submitted to the documentation repository [link](MicrosoftDocs/WindowsCommunityToolkitDocs#511)
- [x] Sample in sample app has been added / updated (for bug fixes / features)    
- [x] Contains **NO** breaking changes

Author: msftbot[bot]

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/SystemInformation/SystemInformationCode.bind

@@ -35,7 +35,10 @@
         public bool IsAppUpdated => SystemInformation.Instance.IsAppUpdated;
 
         // To get the first version installed
-        public PackageVersion FirstVersionInstalled => SystemInformation.Instance.FirstVersionInstalled;
+        public string FirstVersionInstalled => SystemInformation.Instance.FirstVersionInstalled.ToFormattedString();
+
+        // To get the previous version installed
+        public string PreviousVersionInstalled => SystemInformation.Instance.PreviousVersionInstalled.ToFormattedString();
 
         // To get the first time the app was launched
         public DateTime FirstUseTime => SystemInformation.Instance.FirstUseTime;

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/SystemInformation/SystemInformationPage.xaml

@@ -170,6 +170,18 @@
                 <StackPanel x:Name="Stack13"
                             Margin="10"
                             Orientation="Horizontal">
+                    <TextBlock FontSize="18"
+                               FontWeight="Bold"
+                               Text="Previous version installed:"
+                               TextWrapping="Wrap" />
+                    <TextBlock Margin="20,0"
+                               FontSize="18"
+                               Text="{x:Bind PreviousVersionInstalled}"
+                               TextWrapping="Wrap" />
+                </StackPanel>
+                <StackPanel x:Name="Stack14"
+                            Margin="10"
+                            Orientation="Horizontal">
                     <TextBlock FontSize="18"
                                FontWeight="Bold"
                                Text="First use time:"
@@ -179,7 +191,7 @@
                                Text="{x:Bind FirstUseTime}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack14"
+                <StackPanel x:Name="Stack15"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -191,7 +203,7 @@
                                Text="{x:Bind LaunchTime}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack15"
+                <StackPanel x:Name="Stack16"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -203,7 +215,7 @@
                                Text="{x:Bind LastLaunchTime}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack16"
+                <StackPanel x:Name="Stack17"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -215,7 +227,7 @@
                                Text="{x:Bind LastResetTime, Mode=OneWay}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack17"
+                <StackPanel x:Name="Stack18"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -227,7 +239,7 @@
                                Text="{x:Bind LaunchCount, Mode=OneWay}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack18"
+                <StackPanel x:Name="Stack19"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -239,7 +251,7 @@
                                Text="{x:Bind TotalLaunchCount}"
                                TextWrapping="Wrap" />
                 </StackPanel>
-                <StackPanel x:Name="Stack19"
+                <StackPanel x:Name="Stack20"
                             Margin="10"
                             Orientation="Horizontal">
                     <TextBlock FontSize="18"
@@ -284,6 +296,9 @@
                         <Setter Target="Stack15.Orientation" Value="Vertical" />
                         <Setter Target="Stack16.Orientation" Value="Vertical" />
                         <Setter Target="Stack17.Orientation" Value="Vertical" />
+                        <Setter Target="Stack18.Orientation" Value="Vertical" />
+                        <Setter Target="Stack19.Orientation" Value="Vertical" />
+                        <Setter Target="Stack20.Orientation" Value="Vertical" />
                     </VisualState.Setters>
                 </VisualState>
             </VisualStateGroup>

Microsoft.Toolkit.Uwp.SampleApp/SamplePages/SystemInformation/SystemInformationPage.xaml.cs

@@ -54,6 +54,9 @@ public sealed partial class SystemInformationPage : Page
         // To get the first version installed
         public string FirstVersionInstalled => SystemInformation.Instance.FirstVersionInstalled.ToFormattedString();
 
+        // To get the previous version installed
+        public string PreviousVersionInstalled => SystemInformation.Instance.PreviousVersionInstalled.ToFormattedString();
+
         // To get the first time the app was launched
         public string FirstUseTime => SystemInformation.Instance.FirstUseTime.ToString(Culture.DateTimeFormat);
 

Microsoft.Toolkit.Uwp/Helpers/ObjectStorage/BaseObjectStorageHelper.cs

@@ -4,8 +4,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Reflection;
-using System.Runtime.Serialization;
 using System.Threading.Tasks;
 using Windows.Storage;
 
@@ -77,7 +75,7 @@ public bool KeyExists(string compositeKey, string key)
         /// <param name="key">Key of the object</param>
         /// <param name="default">Default value of the object</param>
         /// <returns>The T object</returns>
-        public T Read<T>(string key, T @default = default(T))
+        public T Read<T>(string key, T @default = default)
         {
             if (!Settings.Values.TryGetValue(key, out var value) || value == null)
             {
@@ -95,7 +93,7 @@ public bool KeyExists(string compositeKey, string key)
         /// <param name="key">Key of the object</param>
         /// <param name="default">Default value of the object</param>
         /// <returns>The T object</returns>
-        public T Read<T>(string compositeKey, string key, T @default = default(T))
+        public T Read<T>(string compositeKey, string key, T @default = default)
         {
             ApplicationDataCompositeValue composite = (ApplicationDataCompositeValue)Settings.Values[compositeKey];
             if (composite != null)
@@ -120,9 +118,6 @@ public bool KeyExists(string compositeKey, string key)
         /// <param name="value">Object to save</param>
         public void Save<T>(string key, T value)
         {
-            var type = typeof(T);
-            var typeInfo = type.GetTypeInfo();
-
             Settings.Values[key] = serializer.Serialize(value);
         }
 
@@ -182,7 +177,7 @@ public Task<bool> FileExistsAsync(string filePath)
         /// <param name="filePath">Path to the file that contains the object</param>
         /// <param name="default">Default value of the object</param>
         /// <returns>Waiting task until completion with the object in the file</returns>
-        public async Task<T> ReadFileAsync<T>(string filePath, T @default = default(T))
+        public async Task<T> ReadFileAsync<T>(string filePath, T @default = default)
         {
             string value = await StorageFileHelper.ReadTextFromFileAsync(Folder, filePath);
             return (value != null) ? serializer.Deserialize<T>(value) : @default;

Microsoft.Toolkit.Uwp/Helpers/ObjectStorage/LocalObjectStorageHelper.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Runtime.Serialization;
 using Windows.Storage;
 
 namespace Microsoft.Toolkit.Uwp.Helpers