suite_scheduler: Add trigger-type

BUG=None
TEST=./generate

Change-Id: I90e7c618a347da0118cb52ae51a6034a9d79c079
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2753888
Auto-Submit: Brigit Rossbach <brigitr@google.com>
Reviewed-by: Taylor Clark <taylormade@google.com>
Commit-Queue: Taylor Clark <taylormade@google.com>
2 files changed