Remove maybe types from event recorder test.
Remove maybe types from event recorder test.

This tests triggers a warning, causing the test to fail when run
locally. Maybe types are not permissable in D-Bus land.

[endlessm/eos-sdk#3029]

endlessm/eos-metrics,endlessm/eos-metrics,endlessm/eos-metrics,endlessm/eos-metrics,endlessm/eos-metrics,endlessm/eos-metrics