title: Control Center infos are not updated with AVSpeechSynthesizer
body: <p>In my app i'm using the <code>AVSpeechSynthesizer</code> object to use the TTS. I want to update the control center info box with some infos about the content i'm speaking with the synthesizer, but the infos are not displayed in the control center.
  First of all i'm setting the <code>AVAudioSession</code> to work in background with</p>
  
  <pre><code>do {
      try AVAudioSession.sharedInstance().setCategory(.playback, options: .duckOthers)
      try AVAudioSession.sharedInstance().setMode(.default)
      try AVAudioSession.sharedInstance().setActive(true)
  } catch {
      print(error)
  }
  </code></pre>
  
  <p>Then i'm setting the <code>nowPlayingInfo</code> of the <code>MPNowPlayingInfoCenter</code>, setting some <code>MPMediaItemProperty</code> keys, but in the control center there is the music app and not my infos.</p>