Fix: Use ACTION_GET_CONTENT instead of ACTION_OPEN_DOCUMENT for file picking

This change modifies the `startFileExplorer` function to use `Intent.ACTION_GET_CONTENT` instead of `Intent.ACTION_OPEN_DOCUMENT`.

This resolves an issue where `ACTION_OPEN_DOCUMENT`, combined with `Intent.CATEGORY_OPENABLE`, could lead to hangs or crashes when picking files from certain providers like Google Drive, OneDrive, or Dropbox, especially when the files are not available locally on the device. `ACTION_GET_CONTENT` is more suitable for importing a copy of the data.

Author: daniJimen

android/src/main/kotlin/com/mr/flutter/plugin/filepicker/FileUtils.kt

@@ -159,7 +159,7 @@ object FileUtils {
                     intent.putExtra(Intent.EXTRA_MIME_TYPES, allowedExtensions)
                 }
             } else {
-                intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
+                intent = Intent(Intent.ACTION_GET_CONTENT).apply {
                     addCategory(Intent.CATEGORY_OPENABLE)
                     type = this@startFileExplorer.type
                     if (!allowedExtensions.isNullOrEmpty()) {