Separate YogaLayout library from sample app

Summary: The sample app has library-like elements (i.e. the `YogaLayout` and associated files).  This separates them out into a separate tree.

Reviewed By: emilsjolander

Differential Revision: D4558263

fbshipit-source-id: 33f8cec99661ef20e0e882663b554c12ae33c12f

android/sample/BUCK

@@ -1,9 +1,8 @@
-# Copyright (c) 2014-present, Facebook, Inc.
+# Copyright 2014-present, Facebook, Inc.
 # All rights reserved.
 #
-# This source code is licensed under the BSD-style license found in the
-# LICENSE file in the root directory of this source tree. An additional grant
-# of patent rights can be found in the PATENTS file in the same directory.
+# This source code is licensed under the license found in the
+# LICENSE-examples file in the root directory of this source tree.
 
 include_defs('//YOGA_DEFS')
 
@@ -21,6 +20,9 @@ android_resource(
   name = 'res',
   res = 'res',
   package = 'com.facebook.samples.yoga',
+  deps = [
+    ANDROID_RES_TARGET,
+  ],
   visibility = [
     'PUBLIC',
   ],