Fix `art` script for Golem.

https://r.android.com/3473928 (originally https://r.android.com/2643659)
changed `art` script to generate oat files in `dalvik-cache`. On Golem,
the dex file paths are relative, so the script couldn't compute the
right `dalvik-cache` path for them. This CL fixes this issue.

Also, this CL deletes obsolete calls to a function that no longer
exists.

Bug: 400394885
Test: Golem
Change-Id: I1137d2692c4f28134bb85536b6a7861e8ef0467d