ota_extractor: improve logging am: ee293badde

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3164520

Change-Id: I0f9e4e7274777c39f0ddff795631f6c13bedb2e4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>