Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/44722

Add support for bundling, building and uploading on iOS.  I've verified these locally and will enable on CircleCI to validate.

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D57915365

fbshipit-source-id: 1e73918b31f70d337de4d3aee934c8acf88c86d0