DefaultProvisionService logs noisily for monitored service having state "N"

Method DefaultProvisionService.doUpdate(MonitoredService) currently handles only statuses S (suspend polling), R (resume polling), and A (active). For a service with state N (not polled) it logs a WARN-level message Unhandled state: N. This state is not at all uncommon in the real world, so logging at this level about it is just useless noise. We should handle it equivalently to A, which is to say, just break without any logging or action.