Remove downcase from special path helper

app/helpers/projects_helper.rb

@@ -389,7 +389,7 @@ module ProjectsHelper
   end
   def add_special_file_path(project, file_name:, commit_message: nil, branch_name: nil, context: nil)
-    commit_message ||= s_("CommitMessage|Add %{file_name}") % { file_name: file_name.downcase }
+    commit_message ||= s_("CommitMessage|Add %{file_name}") % { file_name: file_name }
     project_new_blob_path(
       project,
       project.default_branch || 'master',

changelogs/unreleased/jramsay-41590-add-readme-case.yml

+---
+title: Fix inconsistent downcase of filenames in prefilled `Add` commit messages
+merge_request: 16232
+author: James Ramsay
+type: fixed