Use instance variable in template to fix checkboxes

app/views/groups/issues.html.haml

-- can_bulk_update = can?(current_user, :admin_issue, @group)
+- @can_bulk_update = can?(current_user, :admin_issue, @group)
 
 - page_title "Issues"
 = content_for :meta_tags do
@@ -12,14 +12,14 @@
     .nav-controls
       = render 'shared/issuable/feed_buttons'
 
-      - if can_bulk_update
+      - if @can_bulk_update
         = render_if_exists 'shared/issuable/bulk_update_button'
 
       = render 'shared/new_project_item_select', path: 'issues/new', label: "New issue", type: :issues, with_feature_enabled: 'issues', with_shared: false, include_projects_in_subgroups: true
 
   = render 'shared/issuable/search_bar', type: :issues
 
-  - if can_bulk_update
+  - if @can_bulk_update
     = render_if_exists 'shared/issuable/group_bulk_update_sidebar', group: @group, type: :issues
 
   = render 'shared/issues'