Fix analysis server to only send SERVER_STATUS when subscribed to.

pkg/analysis_server/test/analysis_server_test.dart

Index: pkg/analysis_server/test/analysis_server_test.dart
diff --git a/pkg/analysis_server/test/analysis_server_test.dart b/pkg/analysis_server/test/analysis_server_test.dart
index 2df3b593430570a30fdf96588c2ee9a3255ae9ff..1d93a5f8a2ee3a70b1f0b677bee42a37c88c9e07 100644
--- a/pkg/analysis_server/test/analysis_server_test.dart
+++ b/pkg/analysis_server/test/analysis_server_test.dart
@@ -34,6 +34,7 @@ main() {
       context.when(callsTo("performAnalysisTask"))
         ..thenReturn(firstResult, 3)
         ..thenReturn(lastResult);
+      helper.server.serverServices.add(ServerService.STATUS);
       helper.server.schedulePerformAnalysisOperation(context);
       // Pump the event queue to make sure the server has finished any
       // analysis.