Cinder: Only talk about helper script upstream

Conditionally include the helper script documentation only when building
the upstream documentation.

Jira: #OSPRH-5385

docs_user/assemblies/assembly_preparing-the-block-storage-service-for-adoption.adoc

@@ -62,4 +62,8 @@ it or doing it quick and dirty. There is no difference in how {block_storage} op
 
 include::../modules/proc_preparing-block-storage-service-by-customizing-configuration.adoc[leveloffset=+1]
 
-include::../modules/proc_preparing-block-storage-service-by-using-agnostic-config-file.adoc[leveloffset=+1]
+include::../modules/proc_preparing-block-storage-service-by-using-agnostic-config-file.adoc[leveloffset=+1]
+
+ifeval::["{build}" == "upstream"]
+include::../modules/con_block-storage-service-config-generation-helper-tool.adoc[leveloffset=+1]
+endif::[]