Fix stop() in samplePlayer when using MediaCodec mode

When stopping media, getBufferPercentage() and getPosition() may
still be called by MediaController, unless we disable it.

Change-Id: I947fbfb2de724bdcb3121ca9fb204c8bea2a84b2
Signed-off-by: Lajos Molnar <lajos@google.com>
Bug: 9516405

proprietary/samplePlayer/src/com/widevine/demo/MediaCodecView.java

@@ -582,6 +582,10 @@ class MediaCodecView extends SurfaceView
             pause();
         }
 
+        if (mMediaController != null) {
+            mMediaController.setEnabled(false);
+        }
+
         if (mCodecStates != null) {
             for (CodecState state : mCodecStates.values()) {
                 state.release();