Use different modulemap for Carthage. (#3636)
Use different modulemap for Carthage. (#3636)

* Use different modulemap for Carthage.

The zip file and Carthage distribution use different modulemaps - use
the correct one for Carthage. Will address #3578 once this is used in
generating the next Carthage release.

* Fix style

firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk