I suppose the reasoning behind having it might be that Android devices typically also have one of the fonts that appears lower in the stack, but before sans-serif... though that's not as likely if you're using a much smaller stack (also it's already quite near the end so... not sure why its typically used... could indeed be just trying to opt out of some manufacturers' undesirable alternative defaults, maybe).
I suppose the reasoning behind having it might be that Android devices typically also have one of the fonts that appears lower in the stack, but before sans-serif... though that's not as likely if you're using a much smaller stack (also it's already quite near the end so... not sure why its typically used... could indeed be just trying to opt out of some manufacturers' undesirable alternative defaults, maybe).