Add attestation certificate parsing and validate for IC vts.

- Added attestation certificate parsing support.
- Added various certificate conversion support.
- Added certification verification support.
- Added tests for the attestation certificate verification.
- Updated the old tests to use the new attestation validation
  implementation.
- Updated GenerateReaderCertificate to use pointer reader private key.

Bug: 154909726

Test: VtsHalIdentityTargetTest
Test: atest android.security.identity.cts

Change-Id: Ibe770e6eaf0b0018d60876926d824204e4eaf732