GitLab

With Goma builders, we have confirmed that
chromium-ci-builder@chops-service-accounts.iam.gserviceaccount.com
works as without using task service account for Goma.
Let me migrate the builders.

Bug: 1105814
Change-Id: Ic4dedf38c59f358909014d4f8b0c9379914bcb2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2378780Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802101}