Move /webrtc/api/android files to /webrtc/sdk/android

webrtc/sdk/android/src/java/org/webrtc/MediaConstraints.java

 /*
  *  Copyright 2013 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 64 matching lines @@
       builder.append(pair.toString());
     }
     return builder.append("]").toString();
   }
 
   public String toString() {
     return "mandatory: " + stringifyKeyValuePairList(mandatory) + ", optional: "
         + stringifyKeyValuePairList(optional);
   }
 }