Backport Ambari-17694 - Kafka listeners property does not show SASL_PLAINTEXT protocol when Kerberos is enabled

Backport Ambari-17694 to Ambari 2.5.1 because the patch was never committed to branch-2.5 and thus did not make it into Ambari 2.5.0.

Most of the changes from Ambari 2.4.x applied without much additional work, however an upgrade path from Ambari 2.5.0 to Ambari 2.5.1 has been created since users of Ambari 2.5.1 may have missed out on the needed changes. This additional work was essentially copying org.apache.ambari.server.upgrade.UpgradeCatalog240#updateKAFKAConfigs to org.apache.ambari.server.upgrade.UpgradeCatalog251#updateKAFKAConfigs} and adding to the unit tests in {{org.apache.ambari.server.upgrade.UpgradeCatalog251Test.

See AMBARI-17694 for more information about the changes.