Accessing tee patches with holding the thread lock.

There is race that the tee patches can be updated from thread loop and
the tee patches can also be accessed when the client has some
operations. In that case, it will be safe to access tee patches with
holding the thread lock.

Bug: 286576245
Test: atest AudioPlaybackCaptureTest
Change-Id: Ia704350ed5b3c914448ee609da33b867e3aa7626