Cleanup onFrameRenderListener handler...

Even if the codec is null (presume it's handler was run down first, this happens in `MediaCodec.stop()`) make sure to run down our own Handler.

library/core/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java

@@ -563,7 +563,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     clearReportedVideoSize();
     clearReportedVideoSize();
     clearRenderedFirstFrame();
     clearRenderedFirstFrame();
     frameReleaseTimeHelper.disable();
     frameReleaseTimeHelper.disable();
-    if (tunnelingOnFrameRenderedListener != null && getCodec() != null) {
+    if (tunnelingOnFrameRenderedListener != null) {
       tunnelingOnFrameRenderedListener.destroyHandler(getCodec());
       tunnelingOnFrameRenderedListener.destroyHandler(getCodec());
     }
     }
     tunnelingOnFrameRenderedListener = null;
     tunnelingOnFrameRenderedListener = null;