* charm-helpers sync for classic charms
* charms.ceph sync for ceph charms
* rebuild for reactive charms
* sync tox.ini files as needed
* sync requirements.txt files to sync to standard
It's useful when multiple storage backends to be connected to Cinder.
The corresponding volume type must be created after a deployment via API
to take effect, e.g., `openstack volume type create VOLUME_TYPE
--property volume_backend_name=BACKEND_NAME`
Please note that there is a regression in upstream as LP: #1879578, so
it doesn't work for Train or later releases until the issue gets fixed.
The other way to have the similar effect is to edit the definition of
__DEFAULT__ volume type via API (available for Train or later releases).
Howevers it's not as flexible as the option in cinder.conf since it
doesn't allow any modification unless all of the volumes with the
__DEFAULT__ type get deleted.
