Add missing licence to findSymlinksPaths

Summary:
Missing licence added. Fixes #15759.
Closes facebook/react-native#15795

Differential Revision: D5768995

Pulled By: hramos

fbshipit-source-id: 2ecad87670f25362344a8da9478a79e731fd0ac2

util/findSymlinksPaths.js

@@ -1,3 +1,12 @@
+/**
+ * Copyright (c) 2015-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.
+ */
+
 const path = require('path');
 const fs = require('fs');