[iOS] REGRESSION(265596@main) Captions fail to render in video-fullscreen mode
<rdar://problem/112496682>
Pull request: https://github.com/WebKit/WebKit/pull/16031
Committed 266243@main (e0a8ad8a73ca): <https://commits.webkit.org/266243@main> Reviewed commits have been landed. Closing PR #16031 and removing active labels.