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

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ieda93f65ca1c441e85bb5351450c0e4684142ee7