Add file name and line number to libsnapshot logs am: 7f0429fba5

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2523500

Change-Id: Id350afd197c33a4f693969070cfa19440edfc9c4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>