AMBARI-15113. UI does not update alert state (alexantonenko)

ambari-web/app/models/alerts/alert_definition.js

@@ -41,8 +41,8 @@ App.AlertDefinition = DS.Model.extend({
   groups: DS.hasMany('App.AlertGroup'),
   reporting: DS.hasMany('App.AlertReportDefinition'),
   parameters: DS.hasMany('App.AlertDefinitionParameter'),
-  lastTriggered: DS.attr('number'),
-  lastTriggeredRaw: DS.attr('number'),
+  lastTriggered: 0,
+  lastTriggeredRaw: 0,
 
   //relates only to SCRIPT-type alert definition
   location: DS.attr('string'),