Fix S to T incremental OTA with XOR disabled am: 67144e53a0 am: 0db43b5ded

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2521157

Change-Id: I4628cee3cb5eb110bc99934ade46181267ce131a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>