protected String getDataDirectoryPath() {
    return getDataDirectoryPath(getCommandParameters());
  }
Attempts to safely retrieve the "data_directory" property from the this action's relevant
command parameters Map.

@return a String indicating the data directory or null (if not found or set)
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/KerberosServerAction.java