Type ReactPropTypesSecret (#7501)

(cherry picked from commit 563f3bb)

Author: vjeux

src/shared/types/ReactPropTypesSecret.js

@@ -6,13 +6,12 @@
  * 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.
  *
+ * @flow
  * @providesModule ReactPropTypesSecret
  */
 
-
 'use strict';
 
-
 const ReactPropTypesSecret = 'SECRET_DO_NOT_PASS_THIS_OR_YOU_WILL_BE_FIRED';
 
 module.exports = ReactPropTypesSecret;