Merge "libsnapshot: add check for updating next_data_pos_" into main am: 004187ac am: d73b1da0

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2896585



Change-Id: I10eff3245a60bc936209476cd81591b7239939a6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>