Treat GR_TEST_UTILS as defined or not, not 1 or 0.

Change-Id: I8d4f3f8e15ea824aadb0deaabea945d301757640
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/747599
Reviewed-by: Greg Daniel <egdaniel@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
170 files changed