In neutron_lib.context module there are two simple helper functions:
get_admin_context and get_admin_context_without_session.
Both returned Context object with is_admin=True but without admin role
set and due to that it wasn't proper admin context when new secure RBAC
policies are used.
With this patch both those helper functions returns properly elevated
Context object with admin role set.
Closes-Bug: #2015987
Change-Id: Ibde6acdb99555a6e43ca253523df7cbe4d150787
09af59caa9