Increase zookeeper.connection.timeout.ms up to 12 sec

Sometimes it happen that kafka gave up to connect to zookeeper
too early, because zookeeper nodes is not ready to service request
during initialization phase.

Change-Id: I90a3bca6f445acbb27a80ecc2f8046717279d12d
Related-PROD: PROD-26420
(cherry picked from commit 09ba95970deedc053c157a10dae1fcbbbc2331fe)
diff --git a/opencontrail/files/kafka/1.1.1/server.properties b/opencontrail/files/kafka/1.1.1/server.properties
index 1fb905c..1e8d55f 100644
--- a/opencontrail/files/kafka/1.1.1/server.properties
+++ b/opencontrail/files/kafka/1.1.1/server.properties
@@ -131,7 +131,7 @@
 zookeeper.connect={% for member in database.members %}{{ member.host }}:2182{% if not loop.last %},{% endif %}{% endfor %}
 
 # Timeout in ms for connecting to zookeeper
-zookeeper.connection.timeout.ms=6000
+zookeeper.connection.timeout.ms=12000
 
 ##################### Confluent Metrics Reporter #######################
 # Confluent Control Center and Confluent Auto Data Balancer integration