The Android Emulator uses QEMU as the hypervisor.
While QEMU appears to emulate Raspberry Pi 2 you should read the documentation about ARM support to see if it fits your needs.
Physical devices have different driver configuration than the emulator.
And if you want emulator to have any performance you'll have to use a different CPU architecture (x86 vs ARM). Please reach up on Adding a New Device in the AOSP documentation (note the layers).
I don't know if you could run a binary AOSP image on RPi on QEMU but it would be slow (and still need to configure fastboot etc.), this thread: https://www.raspberrypi.org/magpi/android-raspberry-pi/ leads me to believe that drivers will be the blocking point.
Another thing that is leading me to say what you want is very difficult is that it sounds like you want load almost arbitrary images. This article on XDA about EFIDroid shows what I think you want but is limited to a set of supported Qualcomm Snapdragon devices.