Merge "Add ATTEST_KEY" am: 41e68bfb11 am: a5d7ebd9a3 am: d34829254c

Original change: https://android-review.googlesource.com/c/platform/hardware/libhardware/+/1584435

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5b34e86622d8b0505ed76621cf2ebbce1b9190fd