Handle the hardcoded configuration values

This patch allows to customize the hardcoded configuration values,
as well as introduce new configuration options for ceilometer services
by configmap template with the specified section:

  ceilometer:
    server:
      configmap:
        DEFAULT:
          rate_limit_interval: 0
          rate_limit_burst: 0
          rate_limit_except_level: CRITICAL
        coordination:
          max_retry_interval: 30
    agent:
      configmap:
        DEFAULT:
          rate_limit_interval: 0
          rate_limit_burst: 0
          rate_limit_except_level: CRITICAL
        coordination:
          max_retry_interval: 30

Change-Id: Ifec9bdf7756fd8e77cd960a13b9176aa6f00d268
Related-Prod: PROD-29627
(cherry picked from commit 7478c662b0a41671ebb76af936948d29e1a04482)
diff --git a/tests/pillar/agent_cluster.sls b/tests/pillar/agent_cluster.sls
index 1ba1dfb..95bd8cf 100644
--- a/tests/pillar/agent_cluster.sls
+++ b/tests/pillar/agent_cluster.sls
@@ -52,3 +52,10 @@
       ha_queues: true
       # Workaround for https://bugs.launchpad.net/ceilometer/+bug/1337715
       rpc_thread_pool_size: 5
+    configmap:
+      DEFAULT:
+        rate_limit_interval: 0
+        rate_limit_burst: 0
+        rate_limit_except_level: CRITICAL
+      coordination:
+        max_retry_interval: 30