Prevent Telecom from holding focus indefinitely

In certain churny conditions, CARSM may receive a notification that says
that we're releasing focus after it's transitioned into a quiescent
state. In these cases, notify CAMSM that all audio operations are
complete (there's nothing to do anyway), since CAMSM waits for
confirmation that CARSM is done before actually releasing focus.

Fixes: 184238880
Test: manual
Change-Id: I88a457394f9a2371278bd1001a9f044bcd651495