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

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

Change-Id: I06e7586b5516b813b976c2c923e948780e48ba4f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>