Changing cow version to read from build am: c145c71e28

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2577011

Change-Id: I027e5b0cf334023c55a5e7d16fff9d6617770b52
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>