Migrate runtime effect sample tests to golden files

Much easier to maintain, especially with an upcoming change to the
sampling syntax.

Change-Id: I378811b7be0afcce5b7e68a942e7b46d96568155
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/441518
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
4 files changed