Exclude forthcoming shadow_utils gm from serialization testing

Change-Id: I1d652f3d4ddc072c47d00f60dcd0c2a526ff52cb
Reviewed-on: https://skia-review.googlesource.com/7877
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
27 files changed
tree: 81bd7c8bddc7df68809bb49e7b283000f6c166ab
  1. .gitignore
  2. infra/
  3. recipe_modules/
  4. recipes.py
  5. recipes/
  6. test.py