v3 cow estimator am: c717f7a3d0

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2954147

Change-Id: Ic34440fe93b7a136b7c893b720534c61cef69a6c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>