[AKS] remove reference to pod security policy

Author: zr-msft

articles/aks/operator-best-practices-cluster-isolation.md

@@ -68,7 +68,7 @@ Logical separation of clusters usually provides a higher pod density than physic
 
 Currently, Kubernetes environments aren't completely safe for hostile multi-tenant usage. In a multi-tenant environment, multiple tenants are working on a common, shared infrastructure. If all tenants cannot be trusted, you will need extra planning to prevent tenants from impacting the security and service of others.
 
-Additional security features, like *Pod Security Policies* or Kubernetes RBAC for nodes, efficiently block exploits. For true security when running hostile multi-tenant workloads, you should only trust a hypervisor. The security domain for Kubernetes becomes the entire cluster, not an individual node. 
+Additional security features, like Kubernetes RBAC for nodes, efficiently block exploits. For true security when running hostile multi-tenant workloads, you should only trust a hypervisor. The security domain for Kubernetes becomes the entire cluster, not an individual node. 
 
 For these types of hostile multi-tenant workloads, you should use physically isolated clusters.