Added controller support to the Android port. An accelerometer 'joystick' is still the first joystick. Supports two analog sticks and 10 buttons (A B X Y L1 R1 DPAD_L DPAD_R DPAD_U DPAD_D). Supports hotplugging and theoretically multiple joysticks but multiple joysticks were not tested. This change bumps the minimum required Android API level to 12 from 10.