[graphite] Partial fix for color emoji and LCD

Fixes the sampling of the texture to read full color instead of just
red. Still need to figure out how to change the paint color for emoji
so they're only affected by the alpha value.

Bug: skia:13118
Bug: b/238757581
Change-Id: I68f3707cdfb40db6efabab2cdd9ee71fff3ead2e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/563456
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
6 files changed