Convert registration welcome CSS to utility classes

ee/app/views/registrations/welcome/_setup_for_company.html.haml

@@ -6,10 +6,10 @@
   .row
     .form-group.col-sm-12
       = f.label :setup_for_company, setup_for_company_label_text, class: 'label-bold'
-      .d-flex.flex-column.flex-lg-row
-        .flex-grow-1
+      .gl-display-flex.gl-flex-direction-column.gl-lg-flex-direction-row
+        .gl-flex-grow-1
           = f.radio_button :setup_for_company, true, class: 'js-setup-for-company'
           = f.label :setup_for_company, _('My company or team'), class: 'normal', value: 'true'
-        .flex-grow-1
+        .gl-flex-grow-1
           = f.radio_button :setup_for_company, false, class: 'js-setup-for-me'
           = f.label :setup_for_company, _('Just me'), class: 'normal', value: 'false'