Fix androidmk module ordering

Java binary modules expect the order of modules in Soong's Android.mk
to match the variant order.  Instead of sorting by name and then
subdir, which will alphabetize the variants, only sort by name and
use sort.Stable to keep the ordering of modules with the same name.

Test: m
Change-Id: Icf3d22bdc9f9c73945d01c2c47468cc1c361035d