[main] Source code updates from dotnet/winforms#1646

dotnet-maestro[bot] wants to merge 3 commits intomaindotnet/dotnet:mainfrom

darc-main-9b352511-3723-4cb6-bb5e-6d118890d287dotnet/dotnet:darc-main-9b352511-3723-4cb6-bb5e-6d118890d287Copy head branch name to clipboard