Merge "libsnapshot: Check for valid snapshots based on current slot" into main...

Merge "libsnapshot: Check for valid snapshots based on current slot" into main am: acdc4848 am: 8ef208f7 am: fccfcec2 am: 237d5888 am: de6c7e3c

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2701654



Change-Id: Ib34fae53c5d4549027b0798e401879a36b835d95
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>