[media] Set video frame color space from SI in FuchsiaVideoDecoder

Currently, it does not set color space but ideally it should as it is
being used by viz and elsewhere and is currently invalid. This color
space should be same as that set for shared image and eventually it
should be set from WrapSharedImage itself.

Bug: 420632430
Change-Id: Ifcd2f28c47a74e0094217a47e624f10b0141c774
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6710763
Reviewed-by: Zijie He <zijiehe@google.com>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Commit-Queue: Saifuddin Hitawala <hitawala@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1483879}