Add an 'art-preopt' test target configuration.

To test the common case of running preopted apps, which are
precompiled pic against an unrelocated image then used with a
relocated image.

Bug: 33192586
Test: run_build_test_target.py art-preopt
Change-Id: Iababf267b90c63afa137f16a85c78a362de4626a