[native] convert useSelectFromGallery to selectFromGallery

Summary: We don't need to use a hook for this function since we are not dealing with state or other react hooks

Test Plan: No flow errors, and I was still able to create a new avatar from a photo in my gallery

Reviewers: ashoat, atul

Reviewed By: ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7573