Notifications are built using the Pulsate CMS Notification builder, there you can set title, sub title, message, buttons, image, however the App Icon for the notification must be set within the App itself.
By default Pulsate uses a "Red Dot" image, but we recommend changing it so users know this is a notification from your App.
If you want to set a new icon for notifications you will need to create two drawable called - "ic_notification" and "ic_notification_large". Add these drawables later to your drawable folders in your project. Make sure to add all drawable folders - drawable-mdpi, drawable-hdpi, drawable-xhdpi, drawable-xxhdpi. drawable-xxxhdpi.
Recommended icon size:
MDPI - 24 x 24 (drawable-mdpi)
HDPI - 36 x 36 (drawable-hdpi)
XHDPI - 48 x 48 (drawable-xhdpi)
XXHDPI - 72 x 72 (drawable-xxhdpi)
XXXHDPI - 96 x 96 (drawable-xxxhdpi)