Update the now playing list after AddrPlayerChanged

The now playing list needs to be updated since the AddrPlayerChanged
notification resolves the NowPlayingList changed notification. This is
to prevent sending an update immediatly after the notification was rejected.

Bug: 34471252
Test: Connect to carkit and switch players and see that the notification
      changed event wasn't sent after a reject
Change-Id: Ifb05d9bcca53a71aff737fa8875fd308fa516ec7