Replace SK_ARRAY_COUNT with std::size() for skia/samplecode

Change-Id: Ibfa2c0efa3e4addf21aa400e3d323675ac0185ef
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/551886
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Herb Derby <herb@google.com>
27 files changed