NuPlayerRenderer: Do not deliver audio too soon after stop

For non-offloaded audio, do not deliver audio data too soon after stop
when in paused mode.  Otherwise the audio MixerThread will keep the
track playing, instead of inactivating the track.

Bug: 23167401
Change-Id: If376148c742fde2d20dc5d23bf0b894fe378e71a
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
index 58bf121..0c17a8a 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
@@ -170,6 +170,7 @@
 
     // modified on only renderer's thread.
     bool mPaused;
+    int64_t mPauseDrainAudioAllowedUs; // time when we can drain/deliver audio in pause mode.
 
     bool mVideoSampleReceived;
     bool mVideoRenderingStarted;