Lower Heat max_template_size for Tempest

The default size leaves a very large padding for users to create larger
templates, but for testing and development a 10kB template is plenty.

This value is specifically meant to mirror upcoming changes to tempest
so that they are unified and can be tested in lock-step.

Change-Id: I0ea9798018a6d864ac04429c3ac89fb374583fb6
diff --git a/lib/heat b/lib/heat
index 58505ab..ef134ec 100644
--- a/lib/heat
+++ b/lib/heat
@@ -121,6 +121,9 @@
     iniset $HEAT_CONF heat_api_cloudwatch bind_host $HEAT_API_CW_HOST
     iniset $HEAT_CONF heat_api_cloudwatch bind_port $HEAT_API_CW_PORT
 
+    # Set limits to match tempest defaults
+    iniset $HEAT_CONF max_template_size 10240
+
     # heat environment
     sudo mkdir -p $HEAT_ENV_DIR
     sudo chown $STACK_USER $HEAT_ENV_DIR