One check for minimum code version supporting e2ee notifs

Summary: This differential ensures that e2ee notifs are sent to devices supporting code version that will be determined during staff e2ee dm's release

Test Plan: Ensure that e2ee notifs work if and only if FUTURE_CODE_VERSION is 0

Reviewers: tomek

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13261