As specified in Phase 1 of the Consistent and Secure Default RBAC
goal [1] policies have been updated to remove "system" scope and
only use "project" scope in all policies.
APIs with policies that previously required "system" scope have been
updated to accept "project" scoped tokens with the "admin" role instead.
[1] https://governance.openstack.org/tc/goals/selected/consistent-and-secure-rbac.html#phase-1
Change-Id: I3b781112fc6ced7b73196f973cefd6a30ef99dd3