InProgress(1) indicates that a TFTP download is underway,
either as a result of a version mismatch at provisioning
or as a result of a upgradeFromMgt request.
CompleteFromProvisioning(2) indicates that the last
software upgrade was a result of version mismatch at
provisioning. CompleteFromMgt(3) indicates that the last
software upgrade was a result of setting
docsDevSwAdminStatus to upgradeFromMgt.
Failed(4) indicates that the last attempted download
failed, ordinarily due to TFTP timeout.