Merge "libfs_avb: Allow overriding the slot suffix." into main am: 30b1c4dd3b am: 8e60a8d6db am: 1937311500 am: 8d73ba78b1 am: 89aa88984a

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2587226

Change-Id: Ifddb72cec69ebf5cb09c9783c6b495486874b79f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>