[native] memoize some reanimated nodes in video-playback-modal

Summary: memoized some of the reanimated nodes in video-playback-modal using React.useMemo()

Test Plan: The zoom in/out animation continues to work as it did previously. Tested on iOS simulator.

Reviewers: ashoat

Reviewed By: ashoat

Subscribers: KatPo, palys-swm, Adrian

Differential Revision: https://phabricator.ashoat.com/D1153