[Discover] Add metric on adding filter (#82961)

Author: Maja Grubic

src/plugins/discover/public/application/angular/discover.js

@@ -65,6 +65,7 @@ const {
   timefilter,
   toastNotifications,
   uiSettings: config,
+  trackUiMetric,
 } = getServices();
 
 import { getRootBreadcrumbs, getSavedSearchBreadcrumbs } from '../helpers/breadcrumbs';
@@ -81,6 +82,7 @@ import {
   DOC_HIDE_TIME_COLUMN_SETTING,
   MODIFY_COLUMNS_ON_SWITCH,
 } from '../../../common';
+import { METRIC_TYPE } from '@kbn/analytics';
 
 const fetchStatuses = {
   UNINITIALIZED: 'uninitialized',
@@ -990,6 +992,9 @@ function discoverController($element, $route, $scope, $timeout, $window, Promise
       operation,
       $scope.indexPattern.id
     );
+    if (trackUiMetric) {
+      trackUiMetric(METRIC_TYPE.CLICK, 'filter_added');
+    }
     return filterManager.addFilters(newFilters);
   };