Increase default lvm vol size for nova to 50Gb

Related-Prod: PRODX-11806
Change-Id: Ica7b5c2e40a8b7f93a38736e8eceab692a7afb29
diff --git a/de/heat-templates/top.yaml b/de/heat-templates/top.yaml
index d574d0e..2d83383 100644
--- a/de/heat-templates/top.yaml
+++ b/de/heat-templates/top.yaml
@@ -295,7 +295,7 @@
     description: >
       The size of loop device for computes to configure LVM on, in gigabytes
     type: number
-    default: 20
+    default: 50
   acmp_lvm_loop_device_size:
     description: >
       The size of loop device for advanced computes to configure LVM on, in gigabytes