veyron/tools/playground: Move the vms to a separate network.

Change-Id: I6a857155f63e8d5f91b24cd3e1c4c54b3b9bc96a
diff --git a/tools/playground/compilerd/pool_template.json b/tools/playground/compilerd/pool_template.json
index 11bed4c..41b54e4 100644
--- a/tools/playground/compilerd/pool_template.json
+++ b/tools/playground/compilerd/pool_template.json
@@ -26,7 +26,7 @@
         "source": "pg-data-20140820"
       }],
       "networkInterfaces": [{
-        "network": "default",
+        "network": "playground",
         "accessConfigs": [{
           "type": "ONE_TO_ONE_NAT",
           "name": "External NAT"