Add missing copyright

Author: dubzzz

packages/expect/src/__tests__/__arbitraries__/sharedSettings.ts

@@ -1,3 +1,11 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+
 import fc from 'fast-check';
 
 // settings for anything arbitrary