Simplify Setting Up HDFS ACL Sentry Permission Synchronization

This was reported by RecordService Zoltan C Toth:
"I tried to set up HDFS ACL and Sentry Permission Synchronisation on the QuickStart VM based on [1], but the NameNode keeps telling me that it needs a principal to set up the sync. Does this mean that I have no choice but to use Kerberos if I want to set up Sentry-HDFS ACL sync? If so, is there an easy way to get this to work on the VM?"

In the short term we should better explain the need for running kerberos with hdfs sync. We should also investigate enabling kerberos in the VM in an extended example as this is how most production users will be using the product.