Replace promotions clear button FA icon with GlIcon close

ee/app/views/shared/promotions/_promote_advanced_search.html.haml

@@ -2,7 +2,7 @@
   .user-callout.promotion-callout.promotion-advanced-search.js-mr-approval-callout#promote_advanced_search{ data: { uid: 'promote_advanced_search_dismissed' } }
     .bordered-box.content-block
       %button.btn.btn-default.close.js-close-callout{ type: 'button', 'aria-label' => _('Dismiss Merge Request promotion') }
-        = icon('times', class: 'dismiss-icon', 'aria-hidden' => 'true')
+        = sprite_icon('close', size: 16, css_class: 'dismiss-icon')
       .svg-container
         = custom_icon('icon_search_avatar')
       .user-callout-copy

ee/app/views/shared/promotions/_promote_burndown_charts.html.haml

@@ -4,7 +4,7 @@
   .user-callout.promotion-callout#promote_burndown_charts{ data: { uid: callout_id } }
     .bordered-box.content-block.promotion-burndown-charts-content
       %button.btn.btn-default.close.js-close-callout{ type: 'button', 'aria-label' => s_('Promotions|Dismiss burndown charts promotion') }
-        = icon('times', class: 'dismiss-icon', 'aria-hidden' => 'true')
+        = sprite_icon('close', size: 16, css_class: 'dismiss-icon')
       .svg-container
         = custom_icon('icon_burndown_charts')
       .user-callout-copy

ee/app/views/shared/promotions/_promote_mr_features.html.haml

@@ -2,7 +2,7 @@
   .user-callout.promotion-callout.append-bottom-20.js-mr-approval-callout#promote_mr_features{ data: { uid: 'promote_mr_features_dismissed' } }
     .bordered-box.content-block
       %button.btn.btn-default.close.js-close-callout{ type: 'button', 'aria-label' => _('Dismiss Merge Request promotion') }
-        = icon('times', class: 'dismiss-icon', 'aria-hidden' => 'true')
+        = sprite_icon('close', size: 16, css_class: 'dismiss-icon')
       .user-callout-copy
         %h4
           - if Gitlab::CurrentSettings.should_check_namespace_plan?

ee/app/views/shared/promotions/_promote_repository_features.html.haml

@@ -2,7 +2,7 @@
   .user-callout.promotion-callout{ id: 'promote_repository_features', data: { uid: 'promote_repository_features_dismissed' } }
     .bordered-box.content-block
       %button.btn.btn-default.close.js-close-callout{ type: 'button', 'aria-label' => 'Dismiss repository features promotion' }
-        = icon('times', class: 'dismiss-icon', 'aria-hidden' => 'true')
+        = sprite_icon('close', size: 16, css_class: 'dismiss-icon')
       .svg-container
         = custom_icon('icon_push_rules')
       .user-callout-copy