libsnapshot: Fix vts_libsnapshot_test.SnapshotUpdateTest#FullUpdateFlow am: 299717115e am: 4327290387 am: 2e094636ab

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/core/+/19263115

Change-Id: Ic6e4266568069b0a20b038cf1ce9e54783304b01
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>