title: MediaPlayer playing STREAM_NOTIFICATION interrupted music playback
body: <p>In my app, I use the following code to play a short notification sound using MediaPlayer with STREAM_NOTIFICATION. The issue is that, when the app plays the notification sound and at the same time music is played at background by music player app, the notification sound will interrupt (pause) the music playing. How can I make my app's notification sound to be played simultaneously with the background music playback? Thanks. </p>
  
  <pre><code>  AssetFileDescriptor afd =
        mResources.openRawResourceFd(resId);
    MediaPlayer mediaPlayer = new MediaPlayer();
    mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
    afd.close();
    mediaPlayer.setAudioStreamType(AudioManager.STREAM_NOTIFICATION);
    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
          mediaPlayer.release();
        }
      });
    mediaPlayer.prepare();
    mediaPlayer.start();
  </code></pre>