- Video track is always marked as adaptive, the resolution is
stripped out (since it's otherwise just set to whatever the
resolution of the first selected variant is), and the max
dimensions are set.
Issue #514
The SubtitleLayout is now properly aligned with the surface.
This means the subtitles remain on top of the video in portrait
mode, rather than being huge and below it.
- Remove simple variant. Maintaining both simple + full is
unnecessary effort.
- Remove need to specify content id in Sample definition,
except where it's actually required (for DRM requests in
the Widevine GTS samples)