AMBARI-2537. NameNode max new size opt should be set to 200M by default. (jaimin)

git-svn-id: https://svn.apache.org/repos/asf/incubator/ambari/trunk@1498809 13f79535-47bb-0310-9956-ffa450edef68

ambari-web/app/data/config_properties.js

@@ -336,7 +336,7 @@ module.exports =
       "name": "namenode_opt_maxnewsize",
       "displayName": "NameNode maximum new generation size",
       "description": "",
-      "defaultValue": "640",
+      "defaultValue": "200",
       "displayType": "int",
       "unit": "MB",
       "isOverridable": false,