Add split support for AAPT2

AAPT2 allows the declaration of a split path, so that build systems
don't need to guess the auto-generated name.

Construct the split path we want from the configurations passed in to
LOCAL_PACKAGE_SPLITS.

Bug:30445078
Change-Id: I06a4148b283d0c6751751ba116e9482c3a6eae5d
2 files changed