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
Merge "Don't pass along schema as an EventLogging argument"