Add option to use system caption style for subtitles

[Luna712]

Describe your suggested feature

Android has system caption style that some apps use for subtitles, I think it would be nice if an option was added to subtitles to use system caption style, which can be attained from CaptioningManager (I think)

Other details

Also another thing is some subtitle settings don't work. Like if you set transparency for background to 100% it doesn't save, unless you lower to 99%.

Acknowledgements

• My suggestion is NOT about adding a new provider
• I have searched the existing issues and this is a new ticket, NOT a duplicate or related to another open issue.