Ensure all image filter tests have "ImageFilter" somewhere in the name.

This is for convenience, so that running
out/Release/dm --match ImageFilter runs them all.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1879553004

Review URL: https://codereview.chromium.org/1879553004
1 file changed