HttpClient in 2.0 fires deprecated and 'new' events.

When debugging, VS subscribes to deprecated events, AppInsights subscribes to 'new' events from 2.0 client (but also listens to old events to support older versions).

AppInsights attempts to filter out old events for 2.0 clients (https://github.com/Microsoft/ApplicationInsights-dotnet-server/blob/develop/Src/DependencyCollector/Shared/Implementation/HttpCoreDiagnosticSourceListener.cs#L560) with IsEnabled callback.
However when there are 2 listeners for diagnostics source, it's enough if just one of them returns true for IsEnabled, then all listeners get the notification.

So, isNetCore20HttpClient check should be done in OnRequest and OnResponse callbacks too.