AudioService: synchronize audio mode and focus for Telecom

make sure that an audio focus abandon by Telecom is delayed until
the corresponding audio mode reset sequence has been completed

Bug: 339030944
Bug: 346573435
Flag: EXEMPT bug fix
Test: repro steps in bug
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:15f9e56e1f898bd34400db8231f2cda71ca4cc91)
Merged-In: If7249e8276c76df710e0fa363f0aad91c511c14f
Change-Id: If7249e8276c76df710e0fa363f0aad91c511c14f