[native] Limit BackgroundIdentityLoginHandler to one try per startup

Summary:
The effect can make it happen multiple times, which can be messy if they're simultaneous. Let's just stick with one try per app startup.

This addresses ENG-8775, the original context for which is here

Depends on D12678

Test Plan: Make sure we only ever log in once per app startup. I had a log for each Redux action and could configure it only appeared once

Reviewers: varun, tomek

Reviewed By: tomek

Differential Revision: https://phab.comm.dev/D12679