Summary:
This diff adds a middleware to the RN development server to prevent processing requests coming from a third-party website.
The way we choose to do it is to block any request that has an origin header and it's different than localhost. This will still allow simulators to work properly while blocking potential external websites to do malign CORS requests.
This is just a first quick measure to block a potential attack vector while we implement full authentication in the RN development server
Reviewed By: mjesun
Differential Revision: D9238674
fbshipit-source-id: b7bdc40dabc2f4d92f5ac84515f93b89efa4e833
Rafael Oleza