Update RandomMusicPlayer sample for new RemoteControlClient APIs, also add media button support

Change-Id: Ia6ad08dd0ec1e67f1cffa2d6cfca2120ee0a96c7

samples/RandomMusicPlayer/src/com/example/android/musicplayer/MainActivity.java

@@ -22,6 +22,7 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.view.KeyEvent;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
@@ -71,7 +72,6 @@ public class MainActivity extends Activity implements OnClickListener {
         mEjectButton.setOnClickListener(this);
     }
 
-    @Override
     public void onClick(View target) {
         // Send the correct intent to the MusicService, according to the button that was clicked
         if (target == mPlayButton)
@@ -119,4 +119,15 @@ public class MainActivity extends Activity implements OnClickListener {
 
         alertBuilder.show();
     }
+
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        switch (keyCode) {
+            case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
+            case KeyEvent.KEYCODE_HEADSETHOOK:
+                startService(new Intent(MusicService.ACTION_TOGGLE_PLAYBACK));
+                return true;
+        }
+        return super.onKeyDown(keyCode, event);
+    }
 }