按照集成步骤集成，flutter module根本就run不起来

完全按照[【集成步骤】](https://github.com/alibaba/flutter_boost/blob/master/docs/install.md)集成，flutter module 报错：
run命令：`flutter run --no-sound-null-safety`
报错信息：
` lib/main.dart:19:7: Error: The implementation of 'schedulingStrategy' in the non-abstract class 'CustomFlutterBinding' does not conform to its interface.
class CustomFlutterBinding extends WidgetsFlutterBinding with BoostFlutterBinding {}
^^^^^^^^^^^^^^^^^^^^
`

Start with docs/install.md and lib/main.dart at line 19, then reproduce the reported failure with `flutter run --no-sound-null-safety`. The integration is complete when the Flutter module runs without the CustomFlutterBinding schedulingStrategy interface error.

Written by the indexing model from the issue text.