media: further resource cleanup for async release

Bug: 158158088
Test: atest CtsMediaTestCases:MediaCodecCapabilitiesTest#testGetMaxSupportedInstances
Test: atest CtsMediaTestCases -- --module-arg CtsMediaTestCases:size:small
Change-Id: Ie8ab527516836624837c96fa4fdae4dcffe18f43
diff --git a/media/jni/android_media_MediaCodec.h b/media/jni/android_media_MediaCodec.h
index 5c34341..a58f9a7 100644
--- a/media/jni/android_media_MediaCodec.h
+++ b/media/jni/android_media_MediaCodec.h
@@ -173,6 +173,7 @@
     enum {
         kWhatCallbackNotify,
         kWhatFrameRendered,
+        kWhatAsyncReleaseComplete,
     };
 
     jclass mClass;
@@ -185,6 +186,7 @@
     bool mGraphicOutput{false};
     bool mHasCryptoOrDescrambler{false};
     std::once_flag mReleaseFlag;
+    std::once_flag mAsyncReleaseFlag;
 
     sp<AMessage> mCallbackNotification;
     sp<AMessage> mOnFrameRenderedNotification;