Move from btn-success to btn-confirm in projects/default_branch directory

app/views/projects/default_branch/_show.html.haml

@@ -28,4 +28,4 @@
               = _("When merge requests and commits in the default branch close, any issues they reference also close.")
               = link_to sprite_icon('question-o'), help_page_path('user/project/issues/managing_issues.md', anchor: 'disabling-automatic-issue-closing'), target: '_blank'
 
-      = f.submit _('Save changes'), class: "gl-button btn btn-success"
+      = f.submit _('Save changes'), class: "gl-button btn btn-confirm"

changelogs/unreleased/btn-confirm-project-default-branch.yml

+---
+title: Move from btn-success to btn-confirm in default_branch directory
+merge_request: 56330
+author: Yogi (@yo)
+type: changed