Merge "Add flag for app-generated attest keys." am: cc9d967deb am: 69bd0bd99d am: 83501604de

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/1591655

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I6ab0d79c2c147028fb5b09f881acd3012b8cba8f