Android-3DS developer here! It could be done, but only by emulation of the ARM CPU which is pretty much impossible to do (for something like ARM11)

However you can run older versions of android like 1.6 on the 3DS since it uses the ARM architechture, and older ARM7TDMI processors can be emulated on the Wii U (ARM7 is used in the GBA)

it's a thing but it's really early

It's PowerPC so no