tspconfig, java, eventgrid, exclude preview from ServiceVersion (#29928)

* exclude preview in eventgrid

* remove namer

Author: weidongxu-microsoft

specification/eventgrid/Azure.Messaging.EventGrid/tspconfig.yaml

@@ -35,10 +35,10 @@ options:
     namespace: "com.azure.messaging.eventgrid.namespaces"
     package-dir: azure-messaging-eventgrid-namespaces
     partial-update: true
-    namer: true
     generate-samples: false
     generate-tests: false
     enable-sync-stack: true
+    service-version-exclude-preview: true
     customization-class: customization/src/main/java/EventGridCustomization.java
     dev-options:
       loglevel: info