Leanplum/Firebase, WebPush: https://gitlab.torproject.org/tpo/applications/fenix/-/tree/tor-browser-79.0-10.0-1/app/src/main/java/org/mozilla/fenix/push
https://gitlab.torproject.org/tpo/applications/fenix/-/blob/tor-browser-79.0-10.0-1/app/src/main/java/org/mozilla/fenix/components/Push.kt
https://gitlab.torproject.org/tpo/applications/fenix/-/blob/tor-browser-79.0-10.0-1/app/src/main/AndroidManifest.xml#L252