Added Snowplow event tracking to Issues import CSV

A "click_button" event will be triggered when the import button
of the Issues import modal is clicked.

app/views/projects/issues/import_csv/_modal.html.haml

@@ -20,5 +20,5 @@
               = _('It must have a header row and at least two columns: the first column is the issue title and the second column is the issue description. The separator is automatically detected.')
               = _('The maximum file size allowed is %{size}.') % { size: number_to_human_size(Gitlab::CurrentSettings.max_attachment_size.megabytes) }
         .modal-footer
-          %button{ type: 'submit', class: 'btn btn-success', title: _('Import issues') }
+          %button{ type: 'submit', class: 'btn btn-success', title: _('Import issues'), data: { track_label: "export_issues_csv", track_event: "click_button"} }
             = _('Import issues')

ee/app/assets/javascripts/pages/projects/issues/index/index.js

@@ -3,4 +3,5 @@ import Stats from 'ee/stats';
 
 document.addEventListener('DOMContentLoaded', () => {
   Stats.bindTrackableContainer('.issues-export-modal');
+  Stats.bindTrackableContainer('.issues-import-modal');
 });

ee/changelogs/unreleased/8775-track-import-issues-csv-usage-on-gitlab-com-with-snowplow.yml

+---
+title: Added Snowplow tracking to issues import
+merge_request: 9067
+author:
+type: added