Replace BluetoothManager (multi-hfp part 3)

Replace BluetoothManager in the rest of Telecom with the functionality
of BluetoothRouteManager. Currently, the Bluetooth stack still
supports only one connected HFP device, so the new multi-device handling
has not yet been tested/verified except through unit tests.

Test: Manual testing
Change-Id: I19f3ab36386a67f797790394a5b5297786af8e77