Remove callbacks and messages in onDestroy().

The Runnable is running after destroying the Cursor, which only happens in onDestroy(). So clean up before that happens.

Bug: 151283186
Test: Built, installed, and set ringtone.
Change-Id: I95c824675e6e710a1dc5d1f8faef2daff6f563e6
Merged-In: I95c824675e6e710a1dc5d1f8faef2daff6f563e6
(cherry picked from commit 2e23b5c013)

packages/SoundPicker/src/com/android/soundpicker/RingtonePickerActivity.java

@@ -333,6 +333,9 @@ public final class RingtonePickerActivity extends AlertActivity implements
 
     @Override
     public void onDestroy() {
+        if (mHandler != null) {
+            mHandler.removeCallbacksAndMessages(null);
+        }
         if (mCursor != null) {
             mCursor.close();
             mCursor = null;