audiopolicy: fix for ringtone and offload music playback concurrency

Root cause: music output is still active when setphonestate and will be
reevaluate routing and change back to normal speaker.

follow the change of https://googleplex-android-review.git.corp.google.com/c/platform/frameworks/av/+/4292147



Bug: 110072502
Test: self-tested over 30 times.

Change-Id: Iec1c85f9cd24e3eae149fa27ad8d1ec2b23019e0
Signed-off-by: Yung Ti Su <andysu@google.com>