[Fix] Store subtitle settings only on user action

This is a follow-up on PR https://github.com/xbmc/xbmc/pull/4921.
Video settings are now stored **only** on user actions.

Thanks @Voyager1 for your help!
This likely should only be done when not in a menu for dvd's. Otherwise user settings is going to end up being toggled on/off by entering dvd menu.