Enable HDFS NameNode High Availability with HDP 2.0.6 plugin

Extend HDP 2.0.6 plugin to include the setup and configuration of the
HDFS NameNode High Availability after creating, configuring and starting
the cluster.

Change-Id: Ic66be5487d5aaa095cdc25b9918a89e3bccfd074
Merge "Enable HDFS NameNode High Availability with HDP 2.0.6 plugin"