Merge branch 'pr-change-manifest-display-to-standalone' into 'master'

Change Web Application Manifest `display` to `standalone`

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/139311



Merged-by: Natalia Tepluhina <ntepluhina@gitlab.com>
Approved-by: Thomas Hutterer <thutterer@gitlab.com>
Approved-by: Natalia Tepluhina <ntepluhina@gitlab.com>
Co-authored-by: Lasse Rosenow <lasse.j.rosenow@gmail.com>

app/views/pwa/manifest.json.erb

@@ -5,7 +5,7 @@
   "description": "<%= appearance_pwa_description %>",
   "start_url": "<%= root_path %>",
   "scope": "<%= root_path %>",
-  "display": "browser",
+  "display": "standalone",
   "orientation": "any",
   "background_color": "#fff",
   "theme_color": "<%= user_theme_primary_color %>",