[native] Simplify current VideoPlaybackModal animations with useValue hook

Summary: Used useValue hook to make code a little more readable.

Test Plan: Animations appear as they did previously. Will test media pipeline scenarios comprehensively after the native video playback diffs.

Reviewers: ashoat, palys-swm

Reviewed By: ashoat

Subscribers: KatPo, zrebcu411, Adrian, subnub, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D778