CallAudioCommunicationDevice: treat TYPE_BUS as TYPE_BUILTIN_SPEAKER

Also, fix two unit test config nits:
- Don't call MockitoAnnotations.initMocks twice (this wipes out super
  class config).
- Test with callAudioCommunicationDeviceRefactor (already rolled out).

Bug: 365800992
Test: com.android.server.telecom.tests.CallAudioRouteTransitionTests#testActiveTransition
Test: com.android.server.telecom.tests.BasicCallTests#testAudioManagerOperations
Test: com.android.server.telecom.tests.CallAudioRouteStateMachineTest#testFocusChangeFromQuiescentSpeaker
Flag: com.android.server.telecom.flags.bus_device_is_a_speaker
Change-Id: Id49d55f8055f28b92876ac97adab6c95d6cb70d5