Run update_engine_unittests on presubmit am: fbfe4c35db am: cad8b062f0 am: 02c0a3e9a1

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2029098

Change-Id: Ie25e71c7b987c9d9fe44e0a67f9e6f7b598a98ea