MediaSession2: Add reset() to the MediaPlayerBase

This would be used in response to
  - MediaController2#play()
  - KEYCODE_MEDIA_STOP

Bug: 64098437
Test: passed MediaComponentTest
Change-Id: I7cd4d855d5e1bf8e4260a9b920f30dfe2eea44e1

api/current.txt

@@ -24345,7 +24345,6 @@ package android.media {
     method public abstract void prepareDrm(java.util.UUID) throws android.media.MediaPlayer2.ProvisioningNetworkErrorException, android.media.MediaPlayer2.ProvisioningServerErrorException, android.media.ResourceBusyException, android.media.UnsupportedSchemeException;
     method public abstract byte[] provideDrmKeyResponse(byte[], byte[]) throws android.media.DeniedByServerException, android.media.MediaPlayer2.NoDrmSchemeException;
     method public abstract void releaseDrm() throws android.media.MediaPlayer2.NoDrmSchemeException;
-    method public abstract void reset();
     method public abstract void restoreDrmKeys(byte[]) throws android.media.MediaPlayer2.NoDrmSchemeException;
     method public void seekTo(long);
     method public abstract void seekTo(long, int);
@@ -24510,6 +24509,7 @@ package android.media {
     method public abstract void play();
     method public abstract void prepare();
     method public abstract void registerPlayerEventCallback(java.util.concurrent.Executor, android.media.MediaPlayerBase.PlayerEventCallback);
+    method public abstract void reset();
     method public abstract void seekTo(long);
     method public abstract void setAudioAttributes(android.media.AudioAttributes);
     method public abstract void setDataSource(android.media.DataSourceDesc);

media/java/android/media/MediaPlayer2.java

@@ -1339,6 +1339,7 @@ public abstract class MediaPlayer2 extends MediaPlayerBase
      * this method, you will have to initialize it again by setting the
      * data source and calling prepare().
      */
+    @Override
     public abstract void reset();
 
     /**

media/java/android/media/MediaPlayerBase.java

@@ -113,6 +113,11 @@ public abstract class MediaPlayerBase implements AutoCloseable {
      */
     public abstract void pause();
 
+    /**
+     * Resets the MediaPlayerBase to its uninitialized state.
+     */
+    public abstract void reset();
+
     /**
      *
      */