CKS: update cloud.kubernetes.cluster.network.offering to dynamic (#11847)

Author: weizhouapache

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

@@ -56,7 +56,7 @@ public interface KubernetesClusterService extends PluggableService, Configurable
             "cloud.kubernetes.cluster.network.offering",
             "DefaultNetworkOfferingforKubernetesService",
             "Name of the network offering that will be used to create isolated network in which Kubernetes cluster VMs will be launched",
-            false,
+            true,
             KubernetesServiceEnabled.key());
     static final ConfigKey<Long> KubernetesClusterStartTimeout = new ConfigKey<Long>("Advanced", Long.class,
             "cloud.kubernetes.cluster.start.timeout",