Unhardcode AZ

Related-Prod: PRODX-3456

Change-Id: I219229c61dcc887e3cd59ffdc256cb29067a68f5
diff --git a/de/heat-templates/fragments/SrvInstancesVM.yaml b/de/heat-templates/fragments/SrvInstancesVM.yaml
index d82bd96..d005f8d 100644
--- a/de/heat-templates/fragments/SrvInstancesVM.yaml
+++ b/de/heat-templates/fragments/SrvInstancesVM.yaml
@@ -70,6 +70,9 @@
       # Don't mount ephemeral0 to /mnt as it's by default
       mounts:
         - [ ephemeral0, null ]
+  availability_zone:
+    type: string
+    default: nova
 
 resources:
 
@@ -127,7 +130,7 @@
       image: { get_param: image }
       flavor: { get_param: flavor }
       key_name: { get_param: key_name }
-      availability_zone: nova
+      availability_zone: { get_param: availability_zone }
       networks:
         - port: { get_resource: accessible_server_port }
         - port: { get_resource: private_floating_server_port }