[automerger skipped] Free ISnapshotManager once update is done am: 47061dfdc4 am: 79495fbaa1 -s ours

am skip reason: skipped by zhangkelvin

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3506416

Change-Id: I094370fd4dc06e4b0597b99986cdc439bad091a5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>