Longsoon does not have to support ARM "command set" (we call ISA: instruction set architecture) to run Android, because Android does not depend on ARM ISA, as Linux does not rely on any specific ISA - X86, AMD64, ARM, MIPS, whatever.

To put it simple for you to understand, Android is more like a C program (not exactly though). You can compile it for ARM, and you can also compile it for Longsoon. This is not difficult. The difficulty is not for Longsoon to support ARM ISA, but to support Android device specification (or peripherals in PC terminology).