Partial revert of AttestationContext refactor.

This CL reverts the changes to
TrustyKeymasterContext::BuildHiddenAuthorizations and
TrustyKeymasterContext::SetBootParams, ensuring none of the
AttestationContext refactor changes are used outside of the
attestation codepath.

Bug: 178136925
Test: Boot and reboot
Change-Id: Ia80f139c5edc04779b5ee6501a3905223ff75b37
2 files changed