[graphite] Fully use SampleCount in TextureInfo::Datas and ContextOptions

These changes build correctly with SampleCount defined as the current
pseudo-enum class and defined as a regular enum class.

Bug: b/452351267
Change-Id: If47fdbb38332893c399e6c064c01ede3a183a776
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1104816
Commit-Queue: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
25 files changed