Explicitly stop the stream when the A2DP session ends

Note: this needs to be done only for the A2DP HW offload scenario.
For the software data path, this will be done by the Audio HAL.

Bug: 80117050
Test: Manual
Change-Id: I4397d219d82d779706e946f0c7f833c1e93e91f4
Merged-In: I4397d219d82d779706e946f0c7f833c1e93e91f4
(cherry picked from commit 6d493bdc7b7cc9d38f6759d08734cce691c6ac45)