Since EXPERIMENTAL Glance v3 API has been removed in favor of
standalone API implementation was added we need to add some
changes in devstack to support it.
Implements blueprint: move-v3-to-glare
Depends-On: I5b7bd4cdcc5f2a40fc4a5f74bcc422fd700c4fb0
Change-Id: Iced3c68010eb6bcd2a6a1ec8f1c6883f84cbe77f