title: MediaControllerCompat.Callback onAudioInfoChanged never gets called
body: <p>I'm using my own volume controller:</p>
  
  <pre><code>        xenoVolumeProvider = new VolumeProviderCompat(VolumeProviderCompat.VOLUME_CONTROL_RELATIVE, maxXenoVolume, XenoAmp.getAndSetPref("xenoVol", maxXenoVolume / 2)) {
              @Override
              public void onAdjustVolume(int direction) {
                  super.onAdjustVolume(direction);
                  actionSetVolumeByTick(direction);
                  //Logger.d("Wart vol=" + mSession.getController().getPlaybackInfo().getCurrentVolume());
              }
          };
          mSession.setPlaybackToRemote(xenoVolumeProvider);
  </code></pre>
  
  <p>While it (surprisingly) works as expected (apart from a bug on Android 4 that causes FC, unsurprisingly) MediaControllerCompat.Callback's onAudioInfoChanged never gets called, although all other callbacks do.</p>
  
  <p>Since Google's MediaController/MediaSession documentation is (unsurprisingly) non-existant maybe I'm missing something. Maybe I should somehow call onAudioInfoChanged myself on each volume change, but HOW?</p>
  
  <p>There's this callback, that works:</p>
  
  <pre><code>        xenoVolumeProvider.setCallback(new VolumeProviderCompat.Callback() {
              @Override
              public void onVolumeChanged(VolumeProviderCompat volumeProvider) {
                  // maybe I can call onAudioInfoChanged from here?
              }
          });
  </code></pre>
  
  <p>but then again how would I call MediaControllerCompat.Callback's onAudioInfoChanged from there? Any ideas?</p>