AudioFlinger: defer restartIfDisabled()

Defer restartIfDisabled() to the end of
the threadLoop worker thread, allowing execution
without any mutexes held. This prevents mutex
order issues.

To accomplish this, we add a DeferredExecutor object
to ThreadBase, which allows adding functors and dtors
to execute at the end of the worker loop,
where no mutexes are held.

Test: atest AudioPlaybackCaptureTest
Bug: 345400492
Bug: 345676143
Change-Id: I1d7f491fc1289882ce67cb7289b3bc1b58e81d23
diff --git a/services/audioflinger/TrackBase.h b/services/audioflinger/TrackBase.h
index 5708c61..a0b85f7 100644
--- a/services/audioflinger/TrackBase.h
+++ b/services/audioflinger/TrackBase.h
@@ -333,6 +333,9 @@
                                     // true for Track, false for RecordTrack,
                                     // this could be a track type if needed later
 
+    void deferRestartIfDisabled();
+    virtual void restartIfDisabled() {}
+
     const wp<IAfThreadBase> mThread;
     const alloc_type     mAllocType;
     /*const*/ sp<Client> mClient;   // see explanation at ~TrackBase() why not const