Use AVKit to support AVPictureInPictureController

[Alex Rupérez]

"If you have a legacy app that employs the deprecated Media Player framework for its video playback, through its MPMoviePlayerViewController and MPMoviePlayerController classes, you must adopt one of the modern iOS video playback frameworks to participate with Picture in Picture."

https://developer.apple.com/library/prerelease/ios/documentation/WindowsViews/Conceptual/AdoptingMultitaskingOniPad/QuickStartForPictureInPicture.html