Currently we leave the context roles empty when loading the stored
context, even though there are roles associated with e.g the trust
scoped token used via loading the stored context. Loading the auth
ref and populating the roles from the token ensure any RBAC performed
on the context roles will work as expected.
Change-Id: I7d699bcf947940357a6eb6ae2d17027ec8d6bd04
Closes-Bug: #1529354
(cherry picked from commit ce46629661)