[automerger skipped] Move asnyc call audio tasks to single thread. am: 7733488114 am: c228c1948a -s ours

am skip reason: Merged-In I16f1b1407ee75abf7115047b088115ebe385323d with SHA-1 7733488114 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Telecomm/+/23917454

Change-Id: I3212d09fe40b34b73fea9d91831fffd967079715
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>