Like android's scroll bars. 像android的滚动条。Forked from onlywsx's extension. 移植自onlywsx的原扩展
Like a scroll bar in the android, activity display the scroll bar, usually when they don't show, don't take any extension process. 像android中滚动条一样，活动时显示滚动条，平常时则不显示,不占扩展进程。
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1.3.0 update:
- migrate to manifest v3
