Added support for USB audio devices

Two types of USB audio devices are defined:
- USB audio device: the audio device in USB device mode while
the Android device is in USB host mode.
- USB audio accessory: the audio device in USB host mode while
the Android device is in USB device mode.

Renamed intents for analog and digital docks to avoid confusion:
 - ACTION_USB_ANLG_HEADSET_PLUG to ACTION_ANALOG_AUDIO_DOCK_PLUG
 - ACTION_USB_DGTL_HEADSET_PLUG to ACTION_DIGITAL_AUDIO_DOCK_PLUG

Factorized code in AudioService broadcast receiver.

Change-Id: I1b6d0257a9d68ecb9495c78c98bac8c67fec7891

Author: Eric Laurent

core/java/android/content/Intent.java

@@ -2000,8 +2000,8 @@ public static Intent createChooser(Intent target, CharSequence title) {
      * @hide
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
-    public static final String ACTION_USB_ANLG_HEADSET_PLUG =
-            "android.intent.action.USB_ANLG_HEADSET_PLUG";
+    public static final String ACTION_ANALOG_AUDIO_DOCK_PLUG =
+            "android.intent.action.ANALOG_AUDIO_DOCK_PLUG";
 
     /**
      * Broadcast Action: A digital audio speaker/headset plugged in or unplugged.
@@ -2015,8 +2015,8 @@ public static Intent createChooser(Intent target, CharSequence title) {
      * @hide
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
-    public static final String ACTION_USB_DGTL_HEADSET_PLUG =
-            "android.intent.action.USB_DGTL_HEADSET_PLUG";
+    public static final String ACTION_DIGITAL_AUDIO_DOCK_PLUG =
+            "android.intent.action.DIGITAL_AUDIO_DOCK_PLUG";
 
     /**
      * Broadcast Action: A HMDI cable was plugged or unplugged
@@ -2034,7 +2034,7 @@ public static Intent createChooser(Intent target, CharSequence title) {
             "android.intent.action.HDMI_AUDIO_PLUG";
 
     /**
-     * Broadcast Action: A USB audio device was plugged in or unplugged.
+     * Broadcast Action: A USB audio accessory was plugged in or unplugged.
      *
      * <p>The intent will have the following extra values:
      * <ul>
@@ -2046,11 +2046,11 @@ public static Intent createChooser(Intent target, CharSequence title) {
      * @hide
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
-    public static final String ACTION_USB_AUDIO_DEVICE_PLUG =
-            "android.intent.action.USB_AUDIO_DEVICE_PLUG";
+    public static final String ACTION_USB_AUDIO_ACCESSORY_PLUG =
+            "android.intent.action.USB_AUDIO_ACCESSORY_PLUG";
 
     /**
-     * Broadcast Action: A USB audio accessory was plugged in or unplugged.
+     * Broadcast Action: A USB audio device was plugged in or unplugged.
      *
      * <p>The intent will have the following extra values:
      * <ul>
@@ -2062,8 +2062,8 @@ public static Intent createChooser(Intent target, CharSequence title) {
      * @hide
      */
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
-    public static final String ACTION_USB_AUDIO_ACCESSORY_PLUG =
-            "android.intent.action.USB_AUDIO_ACCESSORY_PLUG";
+    public static final String ACTION_USB_AUDIO_DEVICE_PLUG =
+            "android.intent.action.USB_AUDIO_DEVICE_PLUG";
 
     /**
      * <p>Broadcast Action: The user has switched on advanced settings in the settings app:</p>

media/java/android/media/AudioManager.java

@@ -2237,6 +2237,14 @@ public boolean isSilentMode() {
      *  docking station
      */
     public static final int DEVICE_OUT_DGTL_DOCK_HEADSET = AudioSystem.DEVICE_OUT_DGTL_DOCK_HEADSET;
+    /** {@hide} The audio output device code for a USB audio accessory. The accessory is in USB host
+     * mode and the Android device in USB device mode
+     */
+    public static final int DEVICE_OUT_USB_ACCESSORY = AudioSystem.DEVICE_OUT_USB_ACCESSORY;
+    /** {@hide} The audio output device code for a USB audio device. The device is in USB device
+     * mode and the Android device in USB host mode
+     */
+    public static final int DEVICE_OUT_USB_DEVICE = AudioSystem.DEVICE_OUT_USB_DEVICE;
     /** {@hide} This is not used as a returned value from {@link #getDevicesForStream}, but could be
      *  used in the future in a set method to select whatever default device is chosen by the
      *  platform-specific implementation.