Fix race in AudioTrack destruction

Bug: 6427369
Change-Id: Id3b4487406235b881f6f0b4b95c5a02a9b797e75
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 9391d16..b5b7adc 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -1461,7 +1461,7 @@
 {
     // must be in this order to avoid a race condition
     Thread::requestExit();
-    mMyCond.signal();
+    resume();
 }
 
 void AudioTrack::AudioTrackThread::pause()