[graphite] Fixup GR_TEST_UTILS uses to GRAPHITE_TEST_UTILS

Change-Id: Icc941ea912c6335404002c13cc935e64236807bd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/639862
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Arman Uguray <armansito@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
4 files changed