The RemoteControlClient API enables media application to have
information such as album art, current song, playback state
be displayed on "remote control displays", as well as be
controlled by "remote controls".
The new API consists in:
- a new class, RemoteControlClient
- new methods in AudioManager to register a RemoteControlClient
- a new class, RemoteControlClient.MetadataEditor to edit and
apply the information associated with a RemoteControlClient,
and which will be displayed on a "remote control display"
Change-Id: I5616085e4ad58ce0bbc1a5953b0a5a28d32f8703
466ade5ad6