Properly report an error for download action write errors am: 430852dc7b

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2605637

Change-Id: I9db2e141482ae0055d10063f00b0dc42cb87bdf2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>