attestation: implement stubs for ex-cryptohome dbus interface

In certain setups (for now, in tpm2 case), cryptohomed bounces
attestation-related messages to attestationd.
Define missing messages in dbus interface and implement empty
stubs for handling them. The actual implementatons and the
corresponding tests will be provided in followup CLs.

TEST=attestationd starts and cryptohome builds for tpm2,
     manually invoking the added methods using
     "cryptohome --action" returns appropriate errors.

Change-Id: I0e7cae92808d487988a591fcf870c3ef760ecaf9
Commit-Ready: Andrey Pronin <>
Tested-by: Andrey Pronin <>
Reviewed-by: Darren Krahn <>
13 files changed