Fix group visibility UI consistency in settings

Closes #18949

app/views/admin/application_settings/_form.html.haml

@@ -15,7 +15,7 @@
       = f.label :default_snippet_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_snippet_visibility, form: f, selected_level: @application_setting.default_snippet_visibility, form_model: ProjectSnippet.new)
-    .form-group.group-visibility-level-holder
+    .form-group.project-visibility-level-holder
       = f.label :default_group_visibility, class: 'control-label col-sm-2'
       .col-sm-10
         = render('shared/visibility_radios', model_method: :default_group_visibility, form: f, selected_level: @application_setting.default_group_visibility, form_model: Group.new)