trustor_user_id not available in v2 trust token

The trust information in the v2 token is missing the trustor_user_id
and impersonation values. This means you are unable to tell who gave
you the trust.

Change-Id: I7ed215b3353079d8ed9514c586d256c1226a2c19
Closes-bug: #1331882
DocImpact
Merge "trustor_user_id not available in v2 trust token"