ART: Split up bitness-dependent checks in apex checker

Add command line argument to define what the expected layout is,
as well as an auto-detect option.

Test: art/build/apex/runtests.sh
Test: manual - hikey
Test: manual - aosp_x86_64
Change-Id: I5ede486b3aeff63f03766aaf1c8150b9f0a36155