[graphite] Default to approx fit textures for layers/filters

Chrome switched to setting this define explicitly in
https://chromium-review.googlesource.com/c/chromium/src/+/5527566
so we can make it the default now and then remove the define in Chrome.

Bug: b/323886653
Change-Id: If2b381e7fe298d5fa72b68ad08558fe788bf7971
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/853099
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: James Godfrey-Kittle <jamesgk@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>