BluetoothRemoteGATTCharacteristic：stopNotifications() 方法
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
BluetoothRemoteGATTCharacteristic.stopNotifications() 方法返回一个当该特性上不再有活动通知时，会兑现为 BluetoothRemoteGATTCharacteristic 实例的 Promise。