GitLab

 -  Add autoconnect functionality for A2DP Sink
 -  Use AudioPatch mechanism for sink playback
 -  AudioFocus approach to manage concurrencies

A2DP Sink: Support for AudioTrack

- add support for audiotrack to render audio data
- add support for AVRCP State to trigger audio
  rendering

AVRCP_CTRL: add support for AVRCP 1.3 Controller

- fill placeholder function for AVRCP 1.3
- add supporting classes to handle AVRCP Commands

AVRCP Controller: Support for retaining volume level and blocking streaming from remote.

- retain volume level on new connection request
- block streaming from remote.

Change-Id: I8c31fd1779b196ced0fb0870855b93263ea331ec