Reland "Remote powerwash on Chromad via policy"

This is a reland of 6ff1599ed15bbd89a0b58ea9590fcf0eaa8e6bd1

Original change's description:
> Remote powerwash on Chromad via policy
>
> Implement remote powerwash on Chromad, using the recently added
> ChromadToCloudMigrationEnabled policy. The powerwash will be used to
> start the migration of AD managed devices into cloud management. Besides
> having the new policy enabled, the device needs to be on the login
> screen and the enrollment ID must have already been uploaded to
> DMServer.
>
> Bug: 1209246
> Change-Id: I6a67b8a8a43c28bc5f03f27e96d0415f69b6bc83
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3141873
> Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
> Reviewed-by: Roman Sorokin <rsorokin@chromium.org>
> Reviewed-by: Colin Blundell <blundell@chromium.org>
> Commit-Queue: Felipe Andrade <fsandrade@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#959123}

Bug: 1209246
Change-Id: Iee9a7c8ee6e7c7877a35668cd15732af101e19eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3389825
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Roman Sorokin <rsorokin@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Felipe Andrade <fsandrade@chromium.org>
Cr-Commit-Position: refs/heads/main@{#960517}