[luci-scheduler] Add max_concurrent_invocations to chromium.lkgr builders

This adds max_concurrent_invocations on a per-builder basis for chromium.lkgr builders.

Bug: 840631
Change-Id: Id45281695c35b7d0f1549183ac5e72fd8e5ae957
Reviewed-on: https://chromium-review.googlesource.com/1073925
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Ryan Tseng <hinoka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562028}
1 file changed