Support rendering subtitles with unset position outside the video bounds

When playing 2:35.1 aspect ratio videos on a 16:9 Television set on Android TV-specific media3 apps such as https://github.com/jellyfin/jellyfin-androidtv/, subtitles are drawn to the video surface rather than the display surface, resulting in subtitles that are much smaller than they should be.

As you can see in the screenshot below, the subtitles should be rendered at least partially on top of the black bars, but they are limited to the video area rather than the display area on a 16:9 television. The original issue, which goes into more detail and discussion about this lack of support for 2.35:1 video on 16:9 television displays, can be found at https://github.com/jellyfin/jellyfin-androidtv/issues/4234

Proposed solution

I propose officially supporting Android TV devices and their 16:9 displays by properly displaying subtitles according to the television display rather than how the video is drawn to the display, so that 2.35:1 aspect videos can have reasonably-sized subtitles when played on 16:9 televisions.

Alternatives considered

Certain Android TV player apps like https://github.com/damontecres/Wholphin and https://github.com/moneytoo/Player work around this issue and a workaround for Jellyfin for Android TV in the form of https://github.com/jellyfin/jellyfin-androidtv/pull/4816 has been submitted, but the developer of Jellyfin for Android TV prefers an officially supported solution for Android TV devices and their (only) 16:9 television displays, which is why I am creating this feature request.