tpm_manager: enable minijail sandboxing This CL makes tpm_manager daemon run inside a minijail sandbox. tpm_managerd now runs as tpm_manager user. This CL also defines the seccomp policy file for amd64 architecture. BUG=brillo:1039 TEST=run tpm_managerd on a DUT CQ-DEPEND=CL:273273 Change-Id: Icb8dbf967a05c0bd26c624ff79127504f21aad19 Reviewed-on: https://chromium-review.googlesource.com/273340 Reviewed-by: Utkarsh Sanghi <[email protected]> Commit-Queue: Utkarsh Sanghi <[email protected]> Tested-by: Utkarsh Sanghi <[email protected]>