看了一下官方文件
Foreground serveices的前幾段就開宗明義的說要有這個提示
Foreground services perform operations that are noticeable to the user.
Each foreground service must show a status bar notification that has a priority of PRIORITY_LOW or higher. That way, users are actively aware that your app is performing a task in the foreground and is consuming system resources. The notification cannot be dismissed unless the service is either stopped or removed from the foreground.