OAuth NullPointerException when using 'keycloak' authorization with 'resource' permissions

When using 'keycloak' authorization the NullPointerException would occur any time the resource would try to match the authorization grant that is a result of a matching 'resource' permissions.

The reason is that a 'resource' permission results in a grant that contains no 'scopes' attribute. KeycloakRBACAuthorizer alway expects 'scopes' attribute, breaking whenever 'resource' permission based grants tries to be matched.

With the fix, the grant without 'scopes' means that any action is granted on the resource as intended by Keycloak Authorization Services 'resource' permissions.