Generate separate Android.bp per snapshot variant

VNDK snapshot now packages not only the primary abi but also the
secondary abi for each build target. To distinguish 32bit srcs
built from 64bit vs 32bit TARGET_ARCHs, each prebuilt is defined
per TARGET_ARCH and included in corresponding phony package,
vndk_v$VER_$ARCH.

Test: python update.py [options]
Bug: 71370248
Change-Id: I1be1d4421b97855a95be6ca0b8efb62e50205a7d
4 files changed