Hi, I’ve set my push notification icon to my logo, however, a [white] circle appears instead.
What am I doing wrong here?
I thought of an idea: Is it a circle because Android doesn’t distinguish notification icons (just generalizes all icons to be white), so the green lines should actually be transparent?
That icon is tricky.
It must be monochromatic, only white on alpha background.
For reference, the quick overview to to convert an icon to a transparent monochrome image in GIMP:
desaturate by luminosity (converts to black+white), layer → transparency → color to alpha (adds transparency), and finally invert colors (flips to white)
The same methods should work on photoshop or your image editor of choice.
I was able to do it in LunaPic.
Estou um pouco confuso sobre como essa função funciona! 
Olá, Eduardo, isso já foi resolvido aqui e não entendi o que você está pedindo. Poderia abrir um novo tópico sobre o seu problema e fornecer alguns detalhes, por favor?