[chromite] Remove the AUTestStage from builders.

We want to stop generating npo control files during AUTest stage.

Generating N to N+1 (npo) control file is not necessary as we already
have sufficient coverage with N to N test as part of the
paygen_au* suites.

So we don't need this stage and its assoicated code.

TEST=Not sure how best to test this change

Change-Id: Iadc9904c4e81770896cf02756f0025f87f5b5eb0
Reviewed-on: https://chromium-review.googlesource.com/665170
Commit-Ready: David Haddock <dhaddock@chromium.org>
Tested-by: David Haddock <dhaddock@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/671455
Reviewed-by: David Haddock <dhaddock@chromium.org>
Trybot-Ready: David Haddock <dhaddock@chromium.org>
5 files changed