Suppress deprecation warning in CallFragment.

webrtc/examples/androidapp/src/org/appspot/apprtc/CallFragment.java

 /*
  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 111 matching lines @@
     }
     if (captureSliderEnabled) {
       captureFormatSlider.setOnSeekBarChangeListener(
           new CaptureQualityController(captureFormatText, callEvents));
     } else {
       captureFormatText.setVisibility(View.GONE);
       captureFormatSlider.setVisibility(View.GONE);
     }
   }
 
+  // TODO(sakal): Replace with onAttach(Context) once we only support API level 23+.
+  @SuppressWarnings("deprecation")
   @Override
   public void onAttach(Activity activity) {
     super.onAttach(activity);
     callEvents = (OnCallEvents) activity;
   }
 }