Bluetooth indicator should depends on call state

Add CallModel listener to BluetoothManager so that it can alter the
bluetooth state when calls change.

Change-Id: Idf0b9a4b8b2247ac5ddf1fcc1d8359c85bb299da
(cherry picked from commit 9f8953efa3983a1cd3f8411636300deab6ad3789)
4 files changed