Renames of extensible enums don't work

[JoshLove-msft]

Trying to rename https://github.com/Azure/azure-rest-api-specs/blob/abd5157cf12219dcd693b6d8edd5334281110af5/specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.Communication/AzureCommunicationServices.tsp#L769, with the following property override:

@@clientName(recordingContentType,
"AcsRecordingContentType",
"csharp"
);

But it doesn't work. This is specific to csharp - it works for other languages.

[chunyu3]

Need to investigate TCGC library why @clientName does not work.