User should need to have "Manage Roles" privilege to see the "Manage Roles" page

Currently, any user clever enough to type, e.g., /openmrs/adminui/metadata/roles/manageRoles.page#/list into their browser can see the "Manage Roles" page, though they won't be able to do any editing. Access to be this page should be restricted to only those users with the "Manage Roles" privilege.