In
https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1096663
we tried to add a new betty-arcnext builder. Unfortunately it runs VMTest and is the slowest builder. As long as the builder was not important it got destroyed on pretty much every run on the CQ. betty-arcnext was fine on other places.

When we marked the builder important it had failing tests that crept in that were arcnext/VMTest specific.

We need a way to bootstrap slow VMTest builders without self-destruction by the master when the important builders pass. (In particular as we are trying to increase VMTest coverage going forward.)