Remove react-native-notifications dependency from project

Summary: This differential removes react-native-notifications dependency from repo. changes in files were not created manually but by running: "yarn remove react-native-notifications" (in native directory) and then yarn cleaninstall (in project root).

Test Plan: Since all react-native-notifications are already removed and replaced, the only test plan we need is to successfully build the app

Reviewers: tomek, atul, ashoat

Reviewed By: ashoat

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D6141