aaudio: use weak pointer to prevent UAF

Avoid using the mServiceEndpoint smart pointer
from multiple threads.

Bug: 74122779
Test: see bug for test instructions
Merged-In: Idaf9e32a163b25e51bde35d6f5ea10a372b5d916
Change-Id: Idaf9e32a163b25e51bde35d6f5ea10a372b5d916
(cherry picked from commit 92c3e26338637a7ddac54988187c89fb0fe49430)
5 files changed