AudioService: Remove Analog Dock from fixed-volume devices

* Many devices identifying as "Analog Docks" have not built in volume controls
  and rely on software volume (See: All Motorola Mods, older 3.5mm docks,
  etc.)

Change-Id: Ie9b97c7b17b882a5d804db398d149bd777ccf5a4
(cherry picked from commit 24ce6c3e)
(cherry picked from commit a6eff9c9)