AVRCP: workaround invalid setBrowsedPlayer id

Some carkits (Ford specifically) send SetBrowsedPlayer with an ID of 0,
which we never send.  Instead of sending back Invalid ID we guess that
they want to set it to the current addressed player.

Bug: 62811071
Bug: 63057931
Test: browse with ford carkit and it works
Change-Id: I744a3193abb3663997e6143aace4fc59a4705864
(cherry picked from commit 819122df)