Merge changes from topic "AutomotiveQBTSync" into qt-qpr1-dev

* changes:
  Return an empty list when the requested node is not in the tree
  AvrcpController Test update
  AVRCP Controller Media Controller not ready
  Allow subsequent requests for media keys to replay the silent audio sample
  HFP Client call status update
  PBAP server, send favorite contacts
  AVRCP Controller Disable Automatic Focus Request
  A2DP Sink: Focus gain while transient loss
  AVRCP Controller State without Browsing
  Add bluetooth prefs for Android Automotive
  MAP Client disconnect state machine if MAS client disconnected
  MAP Client close connection on MNS disconnect
  MAP Client Only connect MNS in connected state
  MAP Client BMessage parser length
  MAP Client support incomming MMS
  PBAP client, download favorite contacts
  AVRCP MediaBrowserService support ACTION_PREPARE
  AVRCP Controller onSkipToQueueItem invalid
  AVRCP Controller getCurrentCalls NPE
  AVRCP Controller transient loss while idle
  AVRCP Controller request focus when idle
  AVRCP Controller AbsoluteVolumeNotification
  Splitting over-the-air downloading into batches
  Use Calendar.Builder for MAP Client timestamp parsing
  AVRCP Controller Shuffle/Repeat support
  Broadcast MAP Client messages oldest first
  DO NOT MERGE: Revert "AVRCP Controller AbsoluteVolumeNotification"
  DO NOT MERGE: Revert "AVRCP Controller transient loss while idle" This revert is reapplied after a few CLs to match change order to AOSP.