Add 32 / 64 bit abi lists to system properties.

Introduce ro.product.cpu.abilist32 / abilist64, which are
comma separated lists of the 32 and 64 bit ABIs that the
device supports. These properties are used by the zygote and
system server to determine what ABI an app should be
started with.

This changes move abilist related make steps out of envsetup.mk
and into config.mk because they depend on variables set by
core/combo/***. Additionally, config.mk performs a few additional
cleanups of these variables (like stripping them) after the
inclusion of envsetup.mk so this seems like a better place to
put them.

bug: 13647418

Change-Id: I3db39bdd761220c5b4966f651892fb592396f9a1