Halve test erofs image size am: 6fb5303589

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2234809

Change-Id: If7e4ac38e4c28d35e297ef53d414076d62bd7401
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>