USB Host Power Enumeration
10 to 1, your phone uses some variation of the USB Battery Charging standard. That is to say, by changing what the phone sees on the usb D+ and D- pins, it changes ho it should charge. Connecting D+ to D- (shorting them together) indicates high speed charging. Connecting them to ground is another, as is leaving them floating (dumb charger) which indicates 500mA draw only.

It can also respond to the Appl standard, where a resistor voltage divider from VUSB to D+ or D- to ground creates a specific voltage on the d+ and d- line, indicating 1.0A charger, or 2.1A charger.

But the Android ADK is an active USB host, like a computer. The usb data lines are in active use. This prevents the phone from seeing the line as a charger, so you can't do any of that.