There is no documentation on how to port an alternative OS to the Intel Galileo board. First, I suggest you to look for the Android hardware specifications to know if those can be met by the hardware of the board. Additionally keep in mind that x86 compatibility wasn’t supported in older Android versions so you have to check for x86 compatibility as well.
Regarding on how to embed a map in Intel Galileo, I’m not aware of any software for that. I suggest you to look for Linux alternatives that work for the kernel version of your OS. About GPS, I suggest you to check the Shield Testing Report for Intel Galileo Board in there are some options you could consider. I hope this helps
The Intel Galileo board comes with a spi-image which is stored in the 8MB Flash memory. The OS would have to be smaller than that to be stored internally so you could use the SD only for storage and still does not guarantee it will work since it is not supported. Also there is no documentation on how to install an alternative OS into the Galileo board. The procedure for flashing a custom Yocto image into the board can be found in the Quark BSP Build Guide.