title: Playing sound through STREAM_ALARM doesn't start from beginning in Marshmallow
body: <p>I'm playing a sound through STREAM_ALARM:</p>
  
  <pre class="lang-java prettyprint-override"><code>MediaPlayer mp = new MediaPlayer();
  mp.setDataSource(context, notificationSoundUri);
  mp.setAudioStreamType(AudioManager.STREAM_ALARM);
  mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
      @Override
      public void onPrepared(MediaPlayer mp) {
          mp.start();
      }
  });
  mp.prepare();
  </code></pre>
  
  <p>It worked ok until I tried on Android 6. On Android 6 sound doesn't play from beginning, so if I play short sounds, no sound is heard. I tried using <code>seekTo(0)</code> and initializing MediaPlayer in other ways.
  It only happens in Android 6 when using STREAM_ALARM (other streams work well).</p>
  
  <p>Any help?</p>
  
  <p>EDIT: I realized that sound actually starts playing from start, but at very low volume, and after about 2 seconds volume increases... do you know how to deactivate this behavior?</p>