Cluster agent WaitUntilReady fails when left to defaults and not all services exist

When the user does not specify any services and does an AgentGroup/GCCCP level waituntilready then we currently default to waiting for all HTTP services. Now that we have updated WaitUntilReady to not consider a missing service as ready this means that it can fail in unexpected ways. We need to configure the diagnostics component so that it will only force a wait for a missing service when that service has been explicitly asked for by the user.