Reland "Move InstallAttributes to chromeos/settings"

This is a reland of aa6c62dce936e966e2db445045dd04414553642b

Original change's description:
> Move InstallAttributes to chromeos/settings
>
> Necessary for moving CrosSettings to chromeos/settings, so it
> can eventually be used by Mustash.
>
> The following changes were necessary:
> 1. Move install_attributes{.h, .cc} and unit_test.cc
> 2. Update c/b/chromeos/BUILD.gn (source) and chromeos/settings/BUILD.gn
> (destination)
> 3. Update chromeos/DEPS to allow a dependency on cloud_policy_constants.h,
> which is included by install_attributes.h
>
> 4. Unfortunately, that same dependency lead to a circular dependency.
> I was able to avoid that by separating out a "common_constants" rule in
> components/policy/core/common, so that chromeos/settings only depends on
> that, and not on all of components/policy. So I had to change
> components/policy/core/common/BUILD.gn
> and I removed an unnecessary include from
> components/policy/core/common/cloud/cloud_policy_constants.cc
>
> 5. Update #include directives for install_attributes to point to new
> location. This is the other 22 files, all with diffs of +1 -1.
>
> Bug: 446937
> Change-Id: Icc8ba19c5fec91b13004b19680ead9c9f8b0a288
> Reviewed-on: https://chromium-review.googlesource.com/c/1264757
> Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
> Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
> Commit-Queue: A Olsen <olsen@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#599140}

Bug: 446937
Change-Id: If20ad953b2cb9c3808415c7c112eec8d0e97915b
Reviewed-on: https://chromium-review.googlesource.com/c/1278750
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Commit-Queue: A Olsen <olsen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599933}
31 files changed