This combining algorithm returns the first permit or return decision returned
by the list of configured PDPs. Steps: Invoke all configured PIPs in order.
- Invoke each PDP in order.
- If a PDP returns a permit or deny, return decision.
- If no PDPs provide a decision, return indeterminate.
Note that entity issuing the decision for each PDP is not considered, that is
the resource owner is not matched with PDP decision issuer. Resource owner is
used only when an indeterminate decision is returned, with no decision from
any PDPs.