Also fix enrollment steps

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f77f4925ac2b43590677b5cfdce55ce161de48a1

commit f77f4925ac2b43590677b5cfdce55ce161de48a1
Author: tnagel <tnagel@chromium.org>
Date: Mon Nov 07 12:12:19 2016

Remove requisition parameter for Chromad.

The server returns an error when the chrome_ad requisition parameter is set,
thus removing it to unblock testing and further work.

BUG= 639066 

Review-Url: https://codereview.chromium.org/2476243002
Cr-Commit-Position: refs/heads/master@{#430255}

[modify] https://crrev.com/f77f4925ac2b43590677b5cfdce55ce161de48a1/chrome/browser/chromeos/policy/device_cloud_policy_initializer.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/81b609d9c117d7d34a5f542d0306873eb6b1db5e

commit 81b609d9c117d7d34a5f542d0306873eb6b1db5e
Author: rsorokin <rsorokin@chromium.org>
Date: Thu Nov 24 16:35:06 2016

Revert of Remove requisition parameter for Chromad. (patchset #1 id:20001 of https://codereview.chromium.org/2476243002/ )

Reason for revert:
Reverting this cause server side was fixed and now works good.

Original issue's description:
> Remove requisition parameter for Chromad.
>
> The server returns an error when the chrome_ad requisition parameter is set,
> thus removing it to unblock testing and further work.
>
> BUG= 639066 
>
> Committed: https://crrev.com/f77f4925ac2b43590677b5cfdce55ce161de48a1
> Cr-Commit-Position: refs/heads/master@{#430255}

TBR=tnagel@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= 639066 

Review-Url: https://codereview.chromium.org/2528923002
Cr-Commit-Position: refs/heads/master@{#434344}

[modify] https://crrev.com/81b609d9c117d7d34a5f542d0306873eb6b1db5e/chrome/browser/chromeos/policy/device_cloud_policy_initializer.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b7329389843816bda2aeeeaa3366721aae3d9b89

commit b7329389843816bda2aeeeaa3366721aae3d9b89
Author: rsorokin <rsorokin@chromium.org>
Date: Thu Nov 24 16:56:27 2016

Remove ignoring device mode from the server.

It was ignored for Active Directory devices cause server was not setup
properly.

BUG= 639066 
TEST=manual

Review-Url: https://codereview.chromium.org/2526283003
Cr-Commit-Position: refs/heads/master@{#434351}

[modify] https://crrev.com/b7329389843816bda2aeeeaa3366721aae3d9b89/chrome/browser/chromeos/policy/enrollment_handler_chromeos.cc