Feat build extra vars

Add a way to pass extra_vars to build time ansible command.

openstack-login/nodeimage.pkr.hcl

@@ -61,5 +61,8 @@ build {
     groups           = ["compute"]
     ansible_env_vars = ["ANSIBLE_HOST_KEY_CHECKING=False"]
     playbook_file    = "./CRI_XCBC/compute-packer.yaml"
+    extra_arguments  = [
+      "--extra-vars", "${var.extra_vars}"
+    ]
   }
 }