Avoids detecting local cores and guessing remote jobs.

No-try: true
Change-Id: I4a825b8dd922802c5f539419313888fd3b21b870
Reviewed-on: https://chromium-review.googlesource.com/876009
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50733}