Use the current item in the existing queue rather than using metadata

GPM adds additional info into the bundle under a specific key which contains
extra metadata. When a carkit (Magneti BMW does this) requests UID 0 with
getItemAttributes, we would construct a queueItem out of the current song.
This breaks with GPM as the metadata returned from getMetadata() from their
MediaController would not be filled or contain this additional bundle. Instead
always use updateNowPlayingList as it can construct a queue with all the info
we have.

Bug: 65166802
Test: Test switching playlists in GPM with Magneti BWM and see that more info
      other than the song title shows up.
Change-Id: Ie96b3a5eccb94b86337936c913c3e81b67745362