Use KubernetesClientBuilder

Directly using `new DefaultKubernetesClient` is deprecated in favour of the builder.

Author: JamesMcNee

src/main/java/cd/go/contrib/elasticagent/KubernetesClientFactory.java

@@ -17,8 +17,8 @@
 package cd.go.contrib.elasticagent;
 
 import io.fabric8.kubernetes.client.ConfigBuilder;
-import io.fabric8.kubernetes.client.DefaultKubernetesClient;
 import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.KubernetesClientBuilder;
 
 import java.util.concurrent.TimeUnit;
 
@@ -80,7 +80,7 @@ private KubernetesClient createClientFor(PluginSettings pluginSettings) {
                 .withCaCertData(pluginSettings.getCaCertData())
                 .withNamespace(pluginSettings.getNamespace());
 
-        return new DefaultKubernetesClient(configBuilder.build());
+        return new KubernetesClientBuilder().withConfig(configBuilder.build()).build();
     }
 
     public void clearOutExistingClient() {