CKS: skip default egress policy check for vpc network offerings (#11998)

This PR fixes #11995

Steps to reproduce the issue
- create a vpc
- create a vpc tier with default offering `DefaultIsolatedNetworkOfferingForVpcNetworks`
- register CKS ISO
- create CKS on the vpc tier

expected: succeed
actual: failed with error `Kubernetes service has not been configured properly to provision Kubernetes clusters`

Author: weizhouapache

plugins/integrations/kubernetes-service/src/main/java/com/cloud/kubernetes/cluster/KubernetesClusterManagerImpl.java

@@ -477,7 +477,7 @@ private boolean isKubernetesServiceNetworkOfferingConfigured(DataCenter zone, Lo
             logger.warn("Network offering: {} does not have necessary services to provision Kubernetes cluster", networkOffering);
             return false;
         }
-        if (!networkOffering.isEgressDefaultPolicy()) {
+        if (!networkOffering.isForVpc() && !networkOffering.isEgressDefaultPolicy()) {
             logger.warn("Network offering: {} has egress default policy turned off should be on to provision Kubernetes cluster", networkOffering);
             return false;
         }