Merge "libsnapshot: update cow estimation" into main am: e343580f am: d37e5420

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2825163



Change-Id: Ie647f839548ec41a9860e727a1b6fb33c620380a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>