[fiddle] Add PRESUBMIT rule to run tools/fiddle/make_all_examples_cpp.py

It will run this only if it detected a change to docs/examples
and runs fairly quickly.

Hopefully it avoids future bitrot like:
https://skia-review.googlesource.com/c/skia/+/423956

Change-Id: I8c6a54faa3a14dfb53260e03d4e6cc61e84b76cc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/423976
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
1 file changed