Annotate large droidstubs modules high_mem

Previously all droidstubs modules were classified as highmem. Annotate
only the huge modules as such, to allow more parallelization of lowmem
droidstubs modules.

Bug: 170701554
Test: NINJA_HIGHMEM_NUM_JOBS=3 m checkapi
Change-Id: I83ae88222110d7afe4009076e951c88a5188ca83