[native] Pause video playback when app is backgrounded/inactive

Summary: Pause video playback when app is backgrounded or inactive based on state.lifecycleState

Test Plan: VideoPlaybackModal changed paused state as expected when switching apps, going to homescreen, opening control center, etc.

Reviewers: ashoat, palys-swm

Reviewed By: ashoat

Subscribers: KatPo, zrebcu411, Adrian, subnub

Differential Revision: https://phabricator.ashoat.com/D881