Compile bitmap_region_decoder on Android

gyp/android_framework_lib.gyp

 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'targets': [
     {
       'target_name': 'libskia',
       'type': 'shared_library',
       'dependencies': [
         'codec.gyp:codec',
         'core.gyp:core',
         'effects.gyp:effects',
         'gpu.gyp:skgpu',
         'images.gyp:images',
         'opts.gyp:opts',
         'pdf.gyp:pdf',
         'ports.gyp:ports',
+        'tools.gyp:bitmap_region_decoder',
         'utils.gyp:utils',
       ],
     },
   ],
 }