Fix missing properties for trackEvent with screen
Fix missing properties for trackEvent with screen

The whole point of this was that ``screen`` events don't track any of
their properties so we need to actually do that. This fixes a bug where
we weren't actually passing them through.

proversity-org/edx-app-ios,Ben21hao/edx-app-ios-new,edx/edx-app-ios,Ben21hao/edx-app-ios-enterprise-new,Ben21hao/edx-app-ios-new,Ben21hao/edx-app-ios-new,edx/edx-app-ios,Ben21hao/edx-app-ios-enterprise-new,edx/edx-app-ios,Ben21hao/edx-app-ios-new,edx/edx-app-ios,appsembler/edx-app-ios,appsembler/edx-app-ios,Ben21hao/edx-app-ios-enterprise-new,Ben21hao/edx-app-ios-enterprise-new,proversity-org/edx-app-ios,appsembler/edx-app-ios,Ben21hao/edx-app-ios-new,edx/edx-app-ios,yrchen/edx-app-ios,yrchen/edx-app-ios,Ben21hao/edx-app-ios-enterprise-new,proversity-org/edx-app-ios,appsembler/edx-app-ios,appsembler/edx-app-ios,proversity-org/edx-app-ios,proversity-org/edx-app-ios,yrchen/edx-app-ios,edx/edx-app-ios,edx/edx-app-ios,proversity-org/edx-app-ios