[automerger skipped] Add attestation certificate parsing and validate for IC vts. am: 57b3479394 am: e7aa4b92c5 -s ours am: f592af6543 -s ours

am skip reason: Change-Id Ibe770e6eaf0b0018d60876926d824204e4eaf732 with SHA-1 cab019aae5 is in history

Change-Id: Ica6e6535edf28206f08c23456504c4c7753665db