Revert "Reland "[swarming] use go isolated when cipd is enabled by default""
Revert "Reland "[swarming] use go isolated when cipd is enabled by default""

This reverts commit f99488fdc5e41616e6cba5ba91797f5f242ecb30.

Reason for revert:
https://chromium-swarm.appspot.com/task?id=49c56f23cc3cfa10
https://chromium-swarm.appspot.com/tasklist?c=name&c=created_ts&c=pending_time&c=duration&c=bot&c=pool-tag&c=state&d=desc&et=1579149109659&f=state%3ABOT_DIED&n=false&s=created_ts&st=1579145400000

Original change's description:
> Reland "[swarming] use go isolated when cipd is enabled by default"
> 
> This is a reland of 5cabf672123718e8b821d54a078e413a2feb3b22
> 
> crrev.com/c/2000354 fixed previous failure.
> 
> Original change's description:
> > [swarming] use go isolated when cipd is enabled by default
> >
> > I want to see this on dev today and deploy to prod tomorrow if it looks
> > good.
> >
> > Bug: 932396
> > Change-Id: I496f7baee8209462bf66446519197bc591fedc80
> > Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/1997521
> > Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
> > Auto-Submit: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
> > Reviewed-by: Junji Watanabe <jwata@google.com>
> 
> Bug: 932396
> Change-Id: I549413a848064df0162f015fd0bb8e7ae2362cc0
> Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2000355
> Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
> Reviewed-by: Junji Watanabe <jwata@google.com>

TBR=maruel@chromium.org,71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org,jwata@google.com,infra-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I28e11a0bcd470a48f69740bd85dde99fccfeca0b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 932396
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2003839
Reviewed-by: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>
Commit-Queue: Takuto Ikuta <71927f930fca81015e0f496c65cd126ab1a692e3@chromium.org>

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py