[native] [14/34] ReactNav6: make all screen params $ReadOnly

Summary:
We never got around to updating all of these. Noticed some non-$ReadOnly screen params while working on ReactNav6 types, so I decided to update all of them.

Depends on D5406

Test Plan: Flow + ran the app on my phone and played around with it

Reviewers: atul, tomek, bartek

Reviewed By: atul

Subscribers: abosh

Differential Revision: https://phab.comm.dev/D5407