Fixed strings import issue (#5998)

* Fixed strings import issue in KubernetesClusterResourceModifierActionWorker

* Use isNoneEmpty

Author: sureshanaparti

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

@@ -76,7 +76,6 @@
 import com.cloud.vm.VirtualMachine;
 import com.cloud.vm.VmDetailConstants;
 import com.cloud.vm.dao.VMInstanceDao;
-import com.google.common.base.Strings;
 import org.apache.cloudstack.api.ApiConstants;
 import org.apache.cloudstack.api.BaseCmd;
 import org.apache.cloudstack.api.command.user.firewall.CreateFirewallRuleCmd;
@@ -188,7 +187,7 @@ protected String updateKubeConfigWithRegistryDetails(String k8sConfig) {
                 registryUrl = detail.getValue();
             }
         }
-        if (!Strings.isNullOrEmpty(registryUsername) && !Strings.isNullOrEmpty(registryPassword) && !Strings.isNullOrEmpty(registryUrl)) {
+        if (StringUtils.isNoneEmpty(registryUsername, registryPassword, registryUrl)) {
             // Update runcmd in the cloud-init configuration to run a script that updates the containerd config with provided registry details
             String runCmd = "- bash -x /opt/bin/setup-containerd";