AIDL 之 in, out, inout

遇到问题，更新API的时候：NotificationManager.aidl:38.76-84: The direction of 'channel' is not specified. parcelable/union can be an in, out, or inout parameter.

即，非基本类型的参数必须声明数据流方向。

https://www.jianshu.com/p/ddbb40c7a251