Fix various AAudio device selection issues

Bug: 65292224
- Audio policy manager should not use an unavailable device when an explicit
route is requested. This causes a device selection made by a client to
become sticky after device disconnection.

Bug: 64945845
- Remove spurious device change callback occuring after registering a
new client to audio server by creating a specific configuration event
for client registration.
- Do not keep strong references to device callback interfaces in
AudioTrack, AudioRecord and AudioSystem.
- Do not update selected device in AudioTrack and AudioRecord when
not active as the new device selection on the stream is because of other
clients activity which is not relevant to an inactive client.

Bug: 65693340
- Fix missing increment of SessionRoute ref count in getInputForAttr() for
MMAP inputs

Test: AAudio CTS tests

Change-Id: I2a01b02e8b064d352004f6065495fd99aee55745