How do I create a disabled NotificationChannel on Huawei devices

Question

I want to create a bunch of Android Oreo NotificationChannels in my app. Some default to on, some to off. For Samsung devices this was easy: I set NotificationManager.IMPORTANCE_NONE on the channels I wanted to be off by default. On a Huawei P20 Pro however, this makes the channels not only enabled but with the highest priority: Making sound, vibrates and displays a popup.

How can I create a channel that is off by default for Huawei P20 pro and other Huawei devices?

Evidence:

Code:

    val chan1 = NotificationChannel(
        "1",
        "None",
        NotificationManager.IMPORTANCE_NONE
    )
    val chan2 = NotificationChannel(
        "2",
        "Min",
        NotificationManager.IMPORTANCE_MIN
    )
    val chan3 = NotificationChannel(
        "3",
        "Default",
        NotificationManager.IMPORTANCE_DEFAULT
    )

    val notificationManager: NotificationManager =
        getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    notificationManager.createNotificationChannels(listOf(chan1, chan2, chan3))

Screenshot: