Make ziparchive-tests run standalone.

We need to (a) tell soong to copy our data and (b) automatically find
our data relative to our executable.

The real point of this is to be able to run these tests in APCT and
presubmit.

Bug: N/A
Test: ran tests on host and device, from a variety of directories
Change-Id: I4c0be1ac60f03953fdd5ba6e3d15b1aaa37ed019