GrPixelConfig is DEAD!!!!!

Bug: skia:6718
Change-Id: Iecad0943b428f7f0e22b45c4cdc7798df00f3e84
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/265982
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
24 files changed