Fix org.wildfly.clustering.service.ServiceSupplier usage

When PassiveServiceSupplier is used to obtain the value of a service for use by metrics, it is generally safe to construct it using OperationContext.getServiceRegistry(false), as it does not affect the MSC state of the target service.

ActiveServiceSupplier, on the other hand, must always be constructed with OperationContext.getServiceRegistry(true). It is meant to obtain the value of an ACTIVEly installed service, thus its get() should never return null. I'd like to convert as many uses of ActiveServiceSupplier to PassiveServiceSupplier as possible.