Update template for 300 nodes deployment for Booking lab

Fix underlay.hot

PROD-36488

Change-Id: I42709b0c9400d41d1bfabe78428f0e94220faef9
diff --git a/tcp_tests/templates/bm-b300-cicd-queens-ovs-maas/underlay.hot b/tcp_tests/templates/bm-b300-cicd-queens-ovs-maas/underlay.hot
index eb9c990..f2a9ef6 100644
--- a/tcp_tests/templates/bm-b300-cicd-queens-ovs-maas/underlay.hot
+++ b/tcp_tests/templates/bm-b300-cicd-queens-ovs-maas/underlay.hot
@@ -2,12 +2,12 @@
 
 heat_template_version: queens
 
-description: MCP environment for bm-cicd-queens-ovs-maas
+description: MCP environment for bm-b300-cicd-queens-ovs-maas
 
 parameters:
   instance_domain:
     type: string
-    default: bm-cicd-queens-ovs-maas.local
+    default: bm-b300-cicd-queens-ovs-maas.local
   mcp_version:
     type: string
   env_name: