title: AVPlayerViewController inside a view is not showing the playback controls
body: <p>I am working with apple tv. I have a UIView inside my UIViewController. I am adding AVPlayerViewController as subview of my UIView. UIView's frame is CGRect(x: 50, y: 50, width: 1344, height: 756). I am setting AVPlayerViewController frame equals to my UIView's frame.</p>
  
  <p><strong>Issue is that video plays fine in its frame but the controls like pause, play, forward etc. are hidden and not working. But when I set frame as CGRect(x: 0, y: 0, width: 1920, height: 1080), controls are visible and working.</strong> </p>
  
  <p><strong>My code is as per below:</strong></p>
  
  <pre><code>    let url = URL(string: "https://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4")
      let item = AVPlayerItem(url: url!)        
      self.player = AVPlayer(playerItem: item)
      self.avplayerController = AVPlayerViewController()
      self.avplayerController.player = self.player
      self.avplayerController.view.frame = videoPreviewLayer.frame
      self.avplayerController.showsPlaybackControls = true
      self.avplayerController.requiresLinearPlayback = true
  
      self.addChildViewController(self.avplayerController)
      self.view.addSubview(self.avplayerController.view)
  
      self.avpController.player?.play()
  </code></pre>
  
  <p>Please help.</p>