Revert "remove legacy 255-biased colormatrix"

This reverts commit ec654f73975f99443c5828f1090a5e186975a431.

Reason for revert: Seems to be breaking the Google3 roll

Original change's description:
> remove legacy 255-biased colormatrix
> 
> Bug: skia:4872
> Bug: skia:9012
> 
> Change-Id: I7c1ac4e94405404fcb13079b5b578a5a26aad02e
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/210628
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> Auto-Submit: Mike Reed <reed@google.com>

TBR=reed@google.com

Change-Id: Ib51de4f5a3f5d28b4870ca61fff43cce96e7426f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:4872, skia:9012
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/211587
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
3 files changed