AMBARI-20693. Principal suffix field should be a non mandatory field in configure identities page of Enable kerberos wizard (akovalenko)

ambari-web/app/data/HDP2/kerberos_descriptor_properties.js

@@ -29,6 +29,11 @@ var properties = [
     "name": "additional_realms",
     "index": 5,
     "placeholderText": "(" + Em.I18n.t("common.optional") + ")"
+  },
+  {
+    "name": "principal_suffix",
+    "index": 6,
+    "placeholderText": "(" + Em.I18n.t("common.optional") + ")"
   }
 ];
 

ambari-web/app/mixins/wizard/addSecurityConfigs.js

@@ -216,7 +216,7 @@ App.AddSecurityConfigs = Em.Mixin.create({
     for (var propertyName in kerberosProperties) {
       var predefinedProperty = this.get('kerberosDescriptorProperties').findProperty('name', propertyName);
       var value = kerberosProperties[propertyName];
-      var isRequired = propertyName == 'additional_realms' ? false : value !== "";
+      var isRequired = ['additional_realms', 'principal_suffix'].contains(propertyName) ? false : value !== "";
       var propertyObject = {
         name: propertyName,
         value: value,