service/client: Add first BLE interface commands

Added the register-ble, unregister-ble, and unregister-all-ble
commands to FCLI. Also added a DeathListener for the IBluetooth
interface to handle the case when bluetoothtbd dies.

Bug: 23793954
Change-Id: I3c549ea59665cf174fb47114b879f679c0aafcb4
1 file changed