face thumbnail fix pragma entry point

mobile/apps/photos/lib/services/machine_learning/face_thumbnail_generator.dart

@@ -7,6 +7,7 @@ import "package:photos/utils/image_ml_util.dart";
 import "package:photos/utils/isolate/isolate_operations.dart";
 import "package:photos/utils/isolate/super_isolate.dart";
 
+@pragma('vm:entry-point')
 class FaceThumbnailGenerator extends SuperIsolate {
   @override
   Logger get logger => _logger;

mobile/apps/photos/lib/utils/isolate/super_isolate.dart

@@ -10,6 +10,7 @@ import "package:photos/models/base/id.dart";
 import "package:photos/utils/isolate/isolate_operations.dart";
 import "package:synchronized/synchronized.dart";
 
+@pragma('vm:entry-point')
 abstract class SuperIsolate {
   Logger get logger;