Prevent deadlock on BluetoothManagerService during a user switch.

During a user switch, BluetoothManagerService restarts its profiles
via BMS.unbindAllBluetoothProfileServices method. This method calls
mContext.unbindService(psc) for each bound bluetooth profile while
holding mProfileServices lock.

But unbinding the bluetooth profile eventually gets
BMS.onServiceDisconnected method to be called, where the same
mProfileServices lock will be tried to get acquired, on a different
thread, which will cause a deadlock.

This CL makes necessary changes to prevent the deadlock.
Detailed analysis document is attached to the bug.

Bug: 300421828
Test: Manual comparison of perfetto traces
Test: atest ServiceBluetoothTests
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:9fe127742e2d1d9d37b89cb606733ff310c31149)
Merged-In: I289b1bea610c24f8d39a1b5e39221721152219d1
Change-Id: I289b1bea610c24f8d39a1b5e39221721152219d1