Reland "stateful_update: Deprecate/Delete"

This reverts commit d13a1beb844955af939956534c20e52ccbd19d5d.

Reason for revert: <Don't use this anymore in provisioning>

Original change's description:
> Revert "stateful_update: Deprecate/Delete"
>
> This reverts commit 48c2e8a369c07d0b4ee1eaa2eba1e4ae13ee0123.
>
> Reason for revert: autoupdater in Autotest is suspected to still need this, and this may be causing increased provision failures.  Revert since it's just removing an otherwise presumed unused file.
>
> Original change's description:
> > stateful_update: Deprecate/Delete
> >
> > stateful_update has been chromitized. We don't need this script anymore.
> >
> > BUG=chromium:1026933
> > TEST=CQ passes
> >
> > Cq-Depend: chromium:2054077
> > Change-Id: Ibb707672a3d421bbc779c042afa9ddb143ef2efc
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2054755
> > Tested-by: Amin Hassani <ahassani@chromium.org>
> > Commit-Queue: Amin Hassani <ahassani@chromium.org>
> > Reviewed-by: Mike Frysinger <vapier@chromium.org>
>
> Bug: chromium:1026933
> Change-Id: If45b6812d35b4cd8f67ee9451013269cbc260d62
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2133291
> Reviewed-by: Allen Li <ayatane@chromium.org>
> Reviewed-by: Amin Hassani <ahassani@chromium.org>
> Commit-Queue: Allen Li <ayatane@chromium.org>
> Tested-by: Allen Li <ayatane@chromium.org>

BUG=chromium:1067434
TEST=None

Change-Id: Ifdf5f960f8f6a8ae790fc81ce95552a44cba03f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2399744
Tested-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
2 files changed