Disable bad gif decode on CG

This will save me the trouble of triaging this bad image over and
over again :).

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1811943002

Review URL: https://codereview.chromium.org/1811943002
2 files changed