Updating the union so the two fields we need to rename are explicitly named. The clientName decorator can't be used, otherwise. (#35423)

Co-authored-by: ripark <[email protected]>

Author: richardpark-msft

specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/Microsoft.Communication/AzureCommunicationServices.tsp

@@ -940,10 +940,10 @@ union recordingFormatType {
   "Wav",
 
   /** MP3 format */
-  "Mp3",
+  Mp3: "Mp3",
 
   /** MP4 format */
-  "Mp4",
+  Mp4: "Mp4",
 
   string,
 }

specification/eventgrid/Azure.Messaging.EventGrid.SystemEvents/propertyNameOverrideGo.tsp

@@ -620,5 +620,7 @@ using Microsoft.EventGrid.SystemEvents;
   "go"
 );
 @@clientName(AcsCallParticipantKind, "ACSCallParticipantRoleKind", "go");
+@@clientName(recordingFormatType.Mp3, "MP3", "go");
+@@clientName(recordingFormatType.Mp4, "MP4", "go");
 
 // [END] ACS renames (and acronym casing)