You need add small icon with two color black or white only. don't use icon with other colors.
NotificationCompat.Builder builder = new NotificationCompat.Builder(service,NOTIFICATION_CHANNEL_ID) .setSmallIcon(R.drawable.ic_black_white)

You need add small icon with two colors one: either black or white. You shouldn't use icon with other colors.
NotificationCompat.Builder builder = new NotificationCompat.Builder(service,NOTIFICATION_CHANNEL_ID) .setSmallIcon(R.drawable.ic_black_white)