I have an Icon (called ‘test.png’) with white drawing 96×96 px in my drawables folder which I set using AndroidInitializationSettings('test'). However, when running the app and triggering a notification the icon is just a grey background, and I get following message in console:

PlatformException(invalid_icon, The resource test could not be found. Please make sure it has been added as a drawable resource to your Android head project., null, null)

What am I doing wrong?
The file exists, is in the correct folder, and is white with transparent background and 96px. Which other hoops do I have to jump through? :'(