10-7959f-1: Allowlist user emails in production for initial canary flipper test

[michaelclement]

To do a minimal test in production we can set our feature flippers to check a list of allowed account emails. This would let us test in production without opening it up to anyone who might land on VA.gov.

Per this document we can allowlist certain accounts to get through flippers on production. This will probably require having a co-worker who is also a veteran since test accounts don't really exist for production.

[michaelclement]

@baltes @marywang2 Just want to make you aware of this. Thanks!