I think many android devices actually mine, but without knowledge of their owners - botnets
There's no known Android mining botnet that is operational. But if there is, you most likely can't get it on your device provided that you use trusted sources for apps such as Google Play. Unless you download some app that manages to slip through Google's checks. There was a botnet with over 300 Play Store apps that was taken down in August.
And to answer OPs question, there probably are some mining apps for android that are legit. You will kill your device and
NEVER make anything by using them.
That's actually very interesting! Botnets are dead... mmm