Make creation of keystone admin endpoint optional
Make creation of keystone admin endpoint optional

The keystone admin endpoint technically isn't different any longer from
the other keystone endpoints in v3 of the API. However, some
applications like heat are still relying on it to exist.

So we make the creation of the admin endpoint during bootstrap optional
here, with the intention to change the default to False once all jobs
that still need this are modified to explicitly require it.

Change-Id: I7ab12141c558186e397c174c248a613d1810011b

openstack-dev/devstack,nawawi/openstack,nawawi/openstack,openstack-dev/devstack