Revert "Mark data streams stats API as internal-only (#108745)" (#109814)

modules/data-streams/src/main/java/org/elasticsearch/datastreams/rest/RestDataStreamsStatsAction.java

@@ -22,7 +22,7 @@ import java.util.List;
 
 import static org.elasticsearch.rest.RestRequest.Method.GET;
 
-@ServerlessScope(Scope.INTERNAL)
+@ServerlessScope(Scope.PUBLIC)
 public class RestDataStreamsStatsAction extends BaseRestHandler {
     @Override
     public String getName() {