builder_config: document gerrit_changes handling

If present, orchestrator.gerrit_changes are now applied unless input
properties say not to.

BUG=chromium:1072042
TEST=generate

Cq-Depend: chromium:2156056
Change-Id: I64e28d61759ba0cddd0b3c5aec67937beb04bd70
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2155988
Tested-by: LaMont Jones <lamontjones@chromium.org>
Commit-Queue: LaMont Jones <lamontjones@chromium.org>
Auto-Submit: LaMont Jones <lamontjones@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
2 files changed