Audio service: restrict conditions to send ACTION_AUDIO_BECOMING_NOISY

Do not send ACTION_AUDIO_BECOMING_NOISY if:
- DEVICE_OUT_REMOTE_SUBMIX is in the selected devices for media streams
- there is no media playback at the time

Bug: 112203196
Test: see repro steps in bug
Change-Id: I9cc8347837de2eb3c9949f81c11bdfb352512804