Remove react-native-firebase dependency from the project

Summary: This differential removes react-native-firebase dependency from the project

Test Plan: Build the app. Repeat test plans for other differentials in this stack to ensure notifications functionality works correctly - there are no other usages of this library in the project this diff stack didn't remove

Reviewers: tomek, bartek, ashoat

Reviewed By: ashoat

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D6414