Remove CONFIRMATION_TOKEN from update parameters.

The CONFIRMATION_TOKEN can only be checked on finish. And this is the
only time it should be passed to keymaster according to spec. The
spurious CONFIRMATION_TOKEN parameter let strict implemenations fail.
This patch prevents the token from being passed to update.

Test: Manually tested with km4 and confirmationdemo.apk
Bug: 78451119
Change-Id: Ib2ac6d77393246700662aa6f1e5c5514ebe38036