Add ExternalEntryPointPayloadProvisionerTest

Author: abh1sar

plugins/hypervisors/external/src/main/java/org/apache/cloudstack/hypervisor/external/provisioner/ExternalEntryPointPayloadProvisioner.java

@@ -460,6 +460,7 @@ public void prepareExtensionEntryPoint(String extensionName, boolean userDefined
         logger.debug("Preparing entry point for Extension [name: {}, user-defined: {}]", extensionName, userDefined);
         if (!userDefined) {
             logger.debug("Skipping preparing entry point for inbuilt extension: {}", extensionName);
+            return;
         }
         String destinationPath = getExtensionEntryPoint(extensionRelativeEntryPoint);
         if (!destinationPath.endsWith(".sh")) {