Add key attestation challenge proto in rejection info. am: 832a408159

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/federated-compute/+/25482935

Change-Id: If897b66cbb7aa395cc02e07d38a49d318748dfae
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>