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/SrvInstancesBMCephOSD.yaml b/de/heat-templates/fragments/SrvInstancesBMCephOSD.yaml
index f2f4cd2..0c92f7a 100644
--- a/de/heat-templates/fragments/SrvInstancesBMCephOSD.yaml
+++ b/de/heat-templates/fragments/SrvInstancesBMCephOSD.yaml
@@ -110,7 +110,7 @@
       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 }