[graphite] Update GMs to have graphite-backed gpu SkImages (take 2)

This makes part of of our testing infrastructure (i.e., the GMs)
compatible with Graphite's more stringent requirements.

Bug: skia:12701
Change-Id: I5e42d93050eccc1e455f46e07b64654ad3d4548c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/531997
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
19 files changed