DecoratedCustomViewStyle

https://developer.android.com/reference/androidx/core/app/NotificationCompat.DecoratedCustomViewStyle

    // Get the layouts to use in the custom notification
    val notificationLayout = RemoteViews(packageName, R.layout.notification_small)
    val notificationLayoutExpanded = RemoteViews(packageName, R.layout.notification_large)

    // Apply the layouts to the notification
    val customNotification = NotificationCompat.Builder(context, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setStyle(NotificationCompat.DecoratedCustomViewStyle())
            .setCustomContentView(notificationLayout)
            .setCustomBigContentView(notificationLayoutExpanded)
            .build()

Custom Remoteview

https://developer.android.com/training/notify-user/custom-notification

object NotificationUtil {

    enum class NotificationStyle(
        var iconId: Int,
        var layoutId: Int,
    ) {
        Style1(R.drawable.lib_widget_icon_notification_launcher,
            R.layout.lib_widget_notification_style_1),
        Style2(R.drawable.lib_widget_icon_notification_launcher,
            R.layout.lib_widget_notification_style_2),
    }

    fun clearNotification(context: Context, notificationId: Int) {
        NotificationManagerCompat.from(context).cancel(notificationId)
    }

    fun notification(
        context: Context,
        notificationId: Int,
        channelId: String,
        paddingIntent: PendingIntent,
        style: NotificationStyle,
    ) {
        notification(context,
            notificationId,
            channelId,
            paddingIntent,
            style.iconId,
            style.layoutId)
    }

    fun notification(
        context: Context,
        notificationId: Int,
        channelId: String,
        paddingIntent: PendingIntent,
        iconId: Int,
        layoutId: Int,
    ) {
        val notificationLayoutExpanded = RemoteViews(context.packageName, layoutId)

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val name = context.getString(R.string.lib_widget_notification_name)
            val descriptionText = context.getString(R.string.lib_widget_notification_descript)
            val importance = NotificationManager.IMPORTANCE_DEFAULT
            val channel = NotificationChannel(channelId, name, importance).apply {
                description = descriptionText
            }
            val notificationManager: NotificationManager =
                context.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
            notificationManager.createNotificationChannel(channel)
        }

        val customNotification = NotificationCompat.Builder(context, channelId)
            .setSmallIcon(iconId)
            .setGroup(context.packageName)
            .setCustomBigContentView(notificationLayoutExpanded)
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .setContentIntent(paddingIntent)
            .setAutoCancel(false)
            .build().apply { flags = Notification.FLAG_ONGOING_EVENT //permanent  }

        NotificationManagerCompat.from(context).notify(notificationId, customNotification)
    }
}



val paddingIntent = PendingIntent.getActivity(this, 0,
            Intent(this, DemoActivity::class.java),
            PendingIntent.FLAG_UPDATE_CURRENT)

NotificationUtil.notification(this, 1, "1", paddingIntent,NotificationUtil.NotificationStyle.Style1)
NotificationUtil.notification(this, 2, "2", paddingIntent,NotificationUtil.NotificationStyle.Style2)

Repeat & .9 png

<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:src="@drawable/lib_widget_icon_notification_background_style3"
    android:tileMode="repeat"
    android:antialias="true"
    android:dither="false"
    android:filter="false"
    android:gravity="left"
    android:autoMirrored="true" />

.9.png