Tidy up license headers [1/n]

Summary: Changelog: [General] [Fixed] - License header cleanup

Reviewed By: yungsters

Differential Revision: D17952695

fbshipit-source-id: 81aa607612ba1357ef7814ef20371335151afe7e

Author: zertosh

Libraries/Animated/src/__tests__/bezier-test.js

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) Facebook, Inc. and its affiliates.
+ * Portions Copyright (c) Facebook, Inc. and its affiliates.
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.

Libraries/Animated/src/bezier.js

@@ -1,5 +1,5 @@
 /**
- * Copyright (c) Facebook, Inc. and its affiliates.
+ * Portions Copyright (c) Facebook, Inc. and its affiliates.
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.