[infra] Refactor recipe properties in gen_tasks.go

Factor out the ones which prevent deduplication. No behavioral changes.

Change-Id: Ie2f8b6e463f9ea09e0c2a2e7c76be144c5b6cb4e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/223935
Reviewed-by: Ben Wagner aka dogben <benjaminwagner@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
1 file changed