Revert "Migrate to avb_add_hash_footer" am: ed0fd2d0b9

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/2123293

Change-Id: I63f1b0057a7eefb41ea1db9610d9ce1c169528af
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>