title: MPNowPlayingInfoCenter and MPRemoteCommandCenter works in simulator but not on device
body: <p>I'm integrating MPNowPlayingInfoCenter into a music playing app. The integration of that and MPRemoteCommandCenter work great when I run it in the iOS simulator. When I run the same code on a device the music controls in Control Center do not change at all. It's as if the app isn't event registering with MPNow and MPRemote centers.</p>
  
  <pre><code>MPNowPlayingInfoCenter *np = [MPNowPlayingInfoCenter defaultCenter];
  
  np.nowPlayingInfo = @{MPMediaItemPropertyTitle:[tracks objectAtIndex:self.currentTrack],
                        MPMediaItemPropertyArtist:currentArtist,
                        MPMediaItemPropertyAlbumTitle:currentAlbum,
                        MPMediaItemPropertyMediaType:@(MPMediaTypeMusic),                                 
                        MPMediaItemPropertyPlaybackDuration:@(self.audioHandler.audioDuration),        
                        MPNowPlayingInfoPropertyElapsedPlaybackTime:@(self.audioHandler.position),
                        MPNowPlayingInfoPropertyPlaybackRate:rate
  };
  </code></pre>
  
  <p>I've got all this good stuff in my view controller life cycle methods:</p>
  
  <pre><code>- (void) viewDidAppear:(BOOL)animated {
      [super viewDidAppear:animated];
  
      [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
  
      [self becomeFirstResponder];
  }
  
  - (void)viewWillDisappear:(BOOL)animated {
  
      // Turn off remote control event delivery
      [[UIApplication sharedApplication] endReceivingRemoteControlEvents];
  
      // Resign as first responder
      [self resignFirstResponder];
  
      [super viewWillDisappear:animated];
  }
  - (BOOL)canBecomeFirstResponder {
      return YES;
  }
  </code></pre>
  
  <p>A couple notes:</p>
  
  <ol>
  <li>I'm not using AVPlayer. I'm using CoreAudio/Audio units to play
  the audio. This part of the app is working fine.</li>
  <li>I'm testing on iOS 7 and iOS 8 only.</li>
  <li>I'm using the Amazing Audio Engine as a CoreAudio wrapper:  <a href="http://theamazingaudioengine.com" rel="nofollow">http://theamazingaudioengine.com</a></li>
  </ol>