Move SkBitmapRegionDecoder to include/android and src/android

src/android/SkBitmapRegionDecoder.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapRegionCanvas.h"
 #include "SkBitmapRegionCodec.h"
 #include "SkBitmapRegionDecoder.h"
@@ skipping 42 matching lines @@
                 SkCodecPrintf("Error: Failed to create codec.\n");
                 return NULL;
             }
             return new SkBitmapRegionCodec(codec.detach());
         }
         default:
             SkASSERT(false);
             return nullptr;
     }
 }