Update MainActivity.java

packages/sensors/example/android/app/src/main/java/io/flutter/plugins/sensorsexample/MainActivity.java

@@ -9,7 +9,9 @@
 import io.flutter.plugins.sensors.SensorsPlugin;
 
 public class MainActivity extends FlutterActivity {
-
+
+  // TODO(cyanglaz): Remove this once v2 of GeneratedPluginRegistrant rolls to stable.
+  // https://github.com/flutter/flutter/issues/42694
   @Override
   public void configureFlutterEngine(FlutterEngine flutterEngine) {
     super.configureFlutterEngine(flutterEngine);