[skif] Update testing-only matrix validation image filter to new API

Bug: b/40040586
Change-Id: I6e2a28a3f06a7e0c86cacb2d4ea003838df1afe5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/743659
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
1 file changed