Re-enable app image loader for userfaultfd. am: 0e60ddb0c0

Original change: https://android-review.googlesource.com/c/platform/art/+/2482335

Change-Id: I1b3cc53bb2c527db71f348993ccd82e25fec6ed8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>