Merge "snapuserd: typecast cow_op->new_block to uint64_t" into main am: 41e9d7d3a2

Original change: https://android-review.googlesource.com/c/platform/system/core/+/3337165

Change-Id: Ia8b4fc4405498ef8de6d67fa96168aba40d77d13
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>