Fix call screening and redirect mode on hearing aid

When in audio modes where the user is not interacting with
the call on the device (call screen and redirect),
voice playback shouldn't affect the dominant volume control
for BT, as this is not what the user is hearing
(it's redirected or going to uplink, not to hearing aid).

Bug: 309814740
Test: see repro sequence
Change-Id: I5192cd6394ecf7eb7c43751cb0384303ccabbf83