OSDOCS-7852: Adding cluster-admin limitation stmt

Author: skrthomas

modules/network-observability-operator-install.adoc

@@ -10,6 +10,7 @@ You can install the Network Observability Operator using the {product-title} web
 .Prerequisites
 
 * If you choose to use Loki, install the link:https://catalog.redhat.com/software/containers/openshift-logging/loki-rhel8-operator/622b46bcae289285d6fcda39[Loki Operator version 5.7+].
+* You must have `cluster-admin` privileges.
 * One of the following supported architectures is required: `amd64`, `ppc64le`, `arm64`, or `s390x`.
 * Any CPU supported by Red Hat Enterprise Linux (RHEL) 9