Add lucicfg-based empty config.

It replaces
https://chromium.googlesource.com/infra/experimental/+/aec6c740484/

Target -dev services only, like before.

R=iannucci@chromium.org

Change-Id: Ifd5035e5dde9e63a1630bb317ac8fe9d4db04925
Reviewed-on: https://chromium-review.googlesource.com/c/infra/experimental/+/3200520
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
6 files changed