Merge "Added 12 various attestation related vts tests. - Check for app id only...

Merge "Added 12 various attestation related vts tests. - Check for app id only if challenge is provided. - Verify self sign certificate works for RSA and Ecdsa. - Verified attestation is generated for encryption keys too. - Verify no attestation is generated for symetric keys. - Verify app id is always required when attestation challenge is   provided to the new key generation. - Verify app id is ignored when challenge is missing. - Verify app id length is properly encoded. - Added vts tests for various attestation success and fail cases."