CleanupPreviousUpdateAction: refactor and add StopActionInternal am: d506deef54 am: bbbb012280 am: 1e29b681f0

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/1439792

Change-Id: I7f705896adce544621889c6805903928122aeaa1