Summary:
This PR modifies the Websocket implementation on iOS to pass cookies to the server. Sending cookies is useful for clients that wish to access protected Websocket endpoints without creating a new authentication protocol.
Closes https://github.com/facebook/react-native/pull/5630
Reviewed By: svcscm
Differential Revision: D2881815
Pulled By: martinbigio
fb-gh-sync-id: 31c1640626cd15447bdb4f2058ae4e34dfa52f88