[native] Update the logged out modal

Summary:
When we're using a new restore flow, only show the sign in and register buttons.

https://linear.app/comm/issue/ENG-9678/introduce-a-restore-button

Depends on D13946

Restore enabled

Restore disabled

Test Plan: Flow, tested that the correct set of buttons is shown depending on the flag.

Reviewers: kamil, angelika, bartek, ashoat

Reviewed By: ashoat

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13906