The package-upgrade action performs package upgrades for the current
OpenStack release.
The code path used is similar to the openstack-upgrade action, with the
difference being that package-upgrade will not execute if an openstack
upgrade is available (based on the openstack-origin setting).
This change includes a charm-helpers sync.
Change-Id: I88ccffad7af2d2e9cddc1f6514ebd07898e117dc
a61f5abc60