unite all locks under BroadcastRadio

- Each layer having separate a lock and making calls to other layers
  while holding lock leads into deadlock.
- Change all of them to use a single lock from the service to avoid
  deadlock.
- Performance impact should be minimal as there are not that many
  players for radio (one app, HAL, and system server) and the amount
  of calls are not that frequent.

Bug: 194818704
Test: atest BroadcastRadioTests
Change-Id: I5f51c0e0a04ae10428f721be508d5579dc1dd837