Merge "Implementation of the policing of transport control key press events...

Merge "Implementation of the policing of transport control key press events among multiple applications competing for the remote control focus. AudioManager defines a new API for applications to use in order to register their BroadcastReceiver for the media button as the one to receive the corresponding intent, but all applications at the same time (in an ordered broadcast). AudioService handles a stack of remote control focus owners. It traps ACTION_MEDIA_BUTTON intents and sends a new intent to the remote control focus owner."