Replace broadcast message clear button FA icon with GlIcon close

app/views/shared/_broadcast_message.html.haml

@@ -2,11 +2,11 @@
 
 %div{ class: "broadcast-message #{'alert-warning' if is_banner} broadcast-#{message.broadcast_type}-message #{opts[:preview] && 'preview'} js-broadcast-notification-#{message.id} gl-display-flex",
   style: broadcast_message_style(message), dir: 'auto' }
-  .flex-grow-1.text-right.pr-2
+  .gl-flex-grow-1.gl-text-right.gl-pr-3
     = sprite_icon('bullhorn', css_class: 'vertical-align-text-top')
   %div{ class: !fluid_layout && 'container-limited' }
     = render_broadcast_message(message)
-  .flex-grow-1.text-right{ style: 'flex-basis: 0' }
+  .gl-flex-grow-1.gl-flex-basis-0.gl-text-right
     - if (message.notification? || message.dismissable?) && opts[:preview].blank?
-      %button.broadcast-message-dismiss.js-dismiss-current-broadcast-notification.btn.btn-link.pl-2.pr-2{ 'aria-label' => _('Close'), :type => 'button', data: { id: message.id, expire_date: message.ends_at.iso8601 } }
-        %i.fa.fa-times
+      %button.broadcast-message-dismiss.js-dismiss-current-broadcast-notification.btn.btn-link.gl-button{ 'aria-label' => _('Close'), :type => 'button', data: { id: message.id, expire_date: message.ends_at.iso8601 } }
+        = sprite_icon('close', size: 16, css_class: 'gl-icon gl-text-white gl-mx-3!')