Return the daemon error code when update_engine_sideload finishes am: c240687b7c am: e7f1bec8a3

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3477895

Change-Id: I44ba3ca8c57729016f8dbbe79b66863fbfa9283c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>