[automerger skipped] Re-enable libsnapshot ImageManagerTest am: c723fca0 am: 37645974 -s ours am: ec909320 -s ours

am skip reason: Change-Id I858661fed7f58d1e2857ed88f5d8e0f5220bf8c2 with SHA-1 c723fca0 is in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/12337395

Change-Id: I533ff7334a883078b9b0feb71cd07ec600f1f109