consolidate examples to 1 matrix type

Change-Id: I40fcf8290608b838cd6bd189f2905b6ce16a12f0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266681
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
8 files changed