Move Bluetooth startup to PHASE_ACTIVITY_MANAGER_READY

For some reason BluetoothManagerService recently has been unable to bind
to the BluetoothService, causing timeouts, which in turn could lead to
Bluetooth not working immediately after boot.

While refactoring that code, the "get name and address" code was also
removed to make the startup sequence more transparent and easier to
debug.

Bug: 25597150
Change-Id: I62ffe4589a76ea8a6db75e3c7599f149db677ea3