Apply new GitLab UI for buttons in new group page

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

@@ -31,7 +31,7 @@
             = render 'shared/group_tips'
     .form-actions
       = f.submit _('Create group'), class: "gl-button btn btn-success"
-      = link_to  _('Cancel'), admin_groups_path, class: "gl-button btn btn-cancel"
+      = link_to  _('Cancel'), admin_groups_path, class: "gl-button btn btn-default btn-cancel"
 
   - else
     .form-actions

app/views/groups/_new_group_fields.html.haml

@@ -18,5 +18,5 @@
     = render_if_exists 'shared/groups/invite_members'
 .row
   .form-actions.col-sm-12
-    = f.submit _('Create group'), class: "btn btn-success"
-    = link_to _('Cancel'), dashboard_groups_path, class: 'btn btn-cancel'
+    = f.submit _('Create group'), class: "btn gl-button btn-success"
+    = link_to _('Cancel'), dashboard_groups_path, class: 'btn gl-button btn-default btn-cancel'

changelogs/unreleased/gl-button-new-group.yml

+---
+title: Apply new GitLab UI for buttons in new group page
+merge_request: 53456
+author: Yogi (@yo)
+type: other