Correct issue with CallAudioRouteController inband ring check.

The existing method being used relied upon BT Device Manger actively
tracking devices, which it no longer does as part of the refactored audio
routing code.

Created a new version that has no dependency on that class tracking.

Test: Ran unit tests.
Test: Manual test for inband ringing.
Flag: com.android.server.telecom.flags.call_audio_communication_device_refactor
Fixes: 391810212
Change-Id: I815d0e106b2bab3c288a7e05e69bafd9b01a8afb