* Split android

* Split iOS

* Update CI

We need to migrate from deprecated react-native-fabric to react-native-firebase.
This PR enables following Firebase features:
* Analytics
* Crashlytics
* Performance

It also tracks screen view without the necessity of HOC.

Future work:
I won't do it in this PR because it's large enough, but we need to log more app events, like 'sent_message', 'open_admin', 'media_upload', etc.