[automerger skipped] Treat ATTEST_KEY keys as signing keys am: fa0d07888f -s ours

am skip reason: Merged-In Icd7af0d1bdcf98155951eb469349a7924e373f9a with SHA-1 b5a5df3c6c is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/keymaster/+/16220524

Change-Id: I2a3e70f9b152692d6ddb9fcc0e32918415bc32c1