Set relative path to ART tests back to `art/$ISA` instead of `test/$ISA`.

This is to address run-test failures. Some of the test logic still
relies on finding test libraries under `/data/nativetest{,64}/art/$ISA`.

This change is a partial revert of 61f071630083775fe64d177455a056daa7071eca.

Test: Run ART run-tests on device
Test: art/build/apex/runtests.sh
Bug: 129534335
Change-Id: I1ce241ff994bfbd789affdcccf360d6f8c62ce61
3 files changed