Create new glance_api.conf template from Ussuri release to
use default_backend and enabled_backends configuration
parameters instead of deprecated stores, default_store
parameters.
Add new config option cinder-volume-types to specify the
volume types in cinder that can be used to store glance
images.
Add logic to update cinder in glance-api configurations
if cinder-volume-service relation is joined.
Also add two flags, cinder_http_retries and
cinder_state_transition_timeout
Closes-Bug: #1905042
Change-Id: Ife649defc9b765b433d7973ab31778f9cb1efdd9
c2f877a7d4