Use json format for manifest URL (rails#52948)

Author: excid3

railties/lib/rails/generators/rails/app/templates/app/views/layouts/application.html.erb.tt

@@ -11,7 +11,7 @@
     <%%= yield :head %>
 
     <%%# Enable PWA manifest for installable apps (make sure to enable in config/routes.rb too!) %>
-    <%%#= tag.link rel: "manifest", href: pwa_manifest_path %>
+    <%%#= tag.link rel: "manifest", href: pwa_manifest_path(format: :json) %>
 
     <link rel="icon" href="/icon.png" type="image/png">
     <link rel="icon" href="/icon.svg" type="image/svg+xml">