Don't pass along schema as an EventLogging argument

Flow's eventlogging tracking code needs to hold onto this schema
value for internal processing, but not pass it along to EL.  Simple
change should be easy to review.

Fixes T78577

Bug: T78577
Change-Id: I5b6c7c40be61a536b9c8b18ed978e6ce25303244
(cherry picked from commit 3e3059ec1de383fd2bbe700d69837deee8fc38bf)