Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52015
Changelog: [Internal]
Add gflags to fantom_tester so we can pass in data like featureFlags
Reviewed By: cortinico
Differential Revision: D76618409
fbshipit-source-id: a18e642a02c405eef972a7418a606a5980253b6a