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

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

Change-Id: I4507e8fab269bb8b5bc87d65f8f91756f1b9ef07
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>