Rework install script to use functions from gerrit

To avoid exceeding configdrive limit move download functons
as a library from gerrit.

Related-Prod: PRODX-3456
Change-Id: I38c8dbff5818fd3362e653ad8b1caa913580d1ec
diff --git a/de/heat-templates/fragments/SrvInstancesVM.yaml b/de/heat-templates/fragments/SrvInstancesVM.yaml
index cb37946..374ec92 100644
--- a/de/heat-templates/fragments/SrvInstancesVM.yaml
+++ b/de/heat-templates/fragments/SrvInstancesVM.yaml
@@ -82,6 +82,9 @@
   kubectl_version:
     type: string
     default: 1.18.8
+  devops_utils_refspec:
+    type: string
+    default: 'master'
 
 resources:
 
@@ -91,7 +94,7 @@
       group: ungrouped
       config:
         str_replace:
-          template: { get_file: ../scripts/instance_boot.sh }
+          template: { get_file: ../scripts/launch.sh }
           params:
             $node_type:  { get_param: node_type }
             $kubernetes_installer: { get_param: kubernetes_installer }
@@ -113,6 +116,7 @@
             $single_node: { get_param: single_node }
             $secure_overlay_enabled: { get_param: secure_overlay_enabled }
             $kubectl_version: { get_param: kubectl_version }
+            $devops_utils_refspec: { get_param: devops_utils_refspec }
 
   inject_files:
     type: "OS::Heat::CloudConfig"