Merge branch '#231191-projects/services/mattermost_slash_commands' into 'master'

Apply GitLab UI button styles to buttons in app/views/projects/services/mattermost_slash_commands directory

See merge request gitlab-org/gitlab!44293

app/views/projects/services/mattermost_slash_commands/_installation_info.html.haml

@@ -2,6 +2,6 @@
   - unless @service.activated?
     .row
       .col-sm-9.offset-sm-3
-        = link_to new_project_mattermost_path(@project), class: 'btn btn-lg' do
+        = link_to new_project_mattermost_path(@project), class: 'btn gl-button btn-lg' do
           = custom_icon('mattermost_logo', size: 15)
           = s_("MattermostService|Add to Mattermost")

changelogs/unreleased/-231191-projects-services-mattermost_slash_commands.yml

+---
+title: Apply GitLab UI button styles to buttons in app/views/projects/services/mattermost_slash_commands
+merge_request: 44293
+author: Lakshit
+type: other