Implement reporting of 3 VPD fields in DeviceReportRequest

Report 3 more VPD fields in DeviceRegisterRequest:
- ethernet_mac0,
- mfg_date,
- doc_mac.

Extract the common part of CloudPolicyClient::Register() and
CloudPolicyClient::RegisterWithCertificates() into the helper method.

BUG=b:124364709
TEST=unit_tests,components_unittests,local device

Change-Id: If7acfb66020c56efcd7034ddd65014157b35b399
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1561107
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Commit-Queue: Polina Bondarenko <pbond@chromium.org>
Auto-Submit: Polina Bondarenko <pbond@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653141}
14 files changed