Make max_message_size customizable

Change-Id: Id9f55733c41a46d4566cfef2ecf41c353a7aa2b4
diff --git a/metadata/service/ceilometer_collector/single.yml b/metadata/service/ceilometer_collector/single.yml
index eacb11d..16f8050 100644
--- a/metadata/service/ceilometer_collector/single.yml
+++ b/metadata/service/ceilometer_collector/single.yml
@@ -5,9 +5,11 @@
 parameters:
   _param:
     ceilometer_collector_poolsize: 100
+    ceilometer_collector_max_message_size: 262144
   heka:
     ceilometer_collector:
       automatic_starting: true
       enabled: true
       influxdb_time_precision: ms
       poolsize: ${_param:ceilometer_collector_poolsize}
+      max_message_size: ${_param:ceilometer_collector_max_message_size}