Allow metrics to be managed even if Quay operator is deployed in a specific namespace

Currently, the metrics component is not managed by the operator if the operator is deployed in a specific namespace. Since installing Quay operator publicly means that everyone can create a QuayRegistry object, limiting the operator to a specific namespace is a security concern and should be the default. With that being the case, we'd like the operator to manage and define the metrics component as it does now when the operator is deployed in openshift-operators namespace.