manila default share type: enable snapshot extra spec

The manila backends which are mainly targeted by deployment and testing
with ci-framework (cephfs, cephfs/NFS, netapp) do all support
snapshots.
Testing snapshots can always be disabled through tempest configuration.
So always define the extra spec for snapshot support in the default
share type.

hooks/playbooks/manila_create_default_resources.yml

@@ -10,3 +10,5 @@
       ansible.builtin.shell: |
         oc -n {{ namespace }} exec -it pod/openstackclient \
           -- openstack share type create default false
+        oc -n {{ namespace }} exec -it pod/openstackclient \
+          -- openstack share type set default --extra-specs snapshot_support=True