[native][lib] "Permanently" make changes for release

Summary:
We made changes to file-utils:mediaConfig and media-gallery-keyboard:fetchPhotos to accommodate video message work while it was in progress. The change in file-utils was for treating animated GIFs as videos... and the change in media-gallery-keyboard was for including videos in the media selection gallery.

Since the ability to send video messages still isn't ready, the changes have to be reverted before every release... and "un-reverted" after each release. This gets pretty tedious and adds some overhead to the release process (two extra commits).

Since video messages aren't actively being worked on, we decided in ENG-170 (https://linear.app/comm/issue/ENG-170/daily-iosandroid-releases) that it was reasonable to make the changes "permanently."

I left some comments in the code near the changes with steps to re-introduce them when work on video messages starts back up.

Test Plan: NA

Reviewers: def-au1t, palys-swm, ashoat

Reviewed By: ashoat

Subscribers: Adrian, yayabosh

Differential Revision: https://phabricator.ashoat.com/D4123