Extend tests to try loading private libs through product and vendor am: 86224fd876 am: 1e13ab0fb0

Original change: https://android-review.googlesource.com/c/platform/art/+/2239933

Change-Id: I7985447716a8617c2a758fd56f1eb65dba07820e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>