Refactor .aar resource compilation

Instead of extracting the aar, and passing the res directory to another rule
(along with a dependency to a different known file), don't keep the
extracted res directory, and pass the aar directly to the resource
compliation rule, which will extract just the res directory.

I need this for my RBE experiments, where non-listed output files won't
exist in other rules.

Test: m
Change-Id: I99074381052cbcebb6a402484abae9ab2e40284f