AudioDeviceBroker: fix communication route update

Fix missing call to onUpdateCommunicationRoute() when the audio mode
is changing from RINGTONE to IN_COMMUNICATION/IN_CALL but the mode owner
remains the same.

Also:
- Rename getPreferredDeviceForComm() to getPreferredCommunicationDevice()
- Add some logging.

Bug: 181108983
Test: manual audio call routing tests
Change-Id: I29827d1c5a4cb0598a60e2cb3eccb9a52b210797