While we assume that glance_additional_stores can be list of mappings
for multistore glance support, bunch of other logic in role still treats
it as simple list and make verifications against it. So in case one
dares to override variable according to our suggestion, they also need
to override bunch of other things.
We change defaults for `glance_available_stores` variable and always
define it as a multistore list of mappings.
Then we introduce a variable `glance_available_store_types` that is a
list of types for each of configured storage.
Logic of how storages are defined in glance config is also changed now.
Storages won't be defined if there's no "default" record for them in
glance_available_stores.
For each new store that deployer wants to provision, they now can pass
`config` key for glance stores, rather then use config overrides.
Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/901041
Change-Id: I1416e0f6e3ed79abd10f468b52fc712d35a61bd2
aa69a6fe5c