Simplify KeyMint setAdditionalAttestationInfo impl am: 29ba069bbe

Original change: https://android-review.googlesource.com/c/platform/system/keymint/+/3364331

Change-Id: I038cd533127cfd3e8c4d918dbd4dad1212c8970c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>