Fixed Application Insights related warnings in dotnet build.

[goh-chunlin]

This PR is to fix the following two warnings.

warning CS0618: 'TelemetryConfiguration.Active' is obsolete: 'We do not recommend using TelemetryConfiguration.Active on .NET Core. See microsoft/ApplicationInsights-dotnet#1152 for more details'

warning CS0618: 'ApplicationInsightsLoggerFactoryExtensions.AddApplicationInsights(ILoggerFactory, IServiceProvider, LogLevel)' is obsolete: 'ApplicationInsightsLoggerProvider is now enabled by default when enabling ApplicationInsights monitoring using UseApplicationInsights extension method on IWebHostBuilder or AddApplicationInsightsTelemetry extension method on IServiceCollection. From 2.7.0-beta3 onwards, calling this method will result in double logging and filters applied will not get applied. If interested in using just logging provider, then please use Microsoft.Extensions.Logging.ApplicationInsightsLoggingBuilderExtensions.AddApplicationInsights from Microsoft.Extensions.Logging.ApplicationInsights package. Read more https://aka.ms/ApplicationInsightsILoggerFaq'

[clairernovotny]

Can you please merge/rebase on top of the master to have a clean build?

[goh-chunlin]

Hi @onovotny, I have merged the new changes. Please review.

Thank you. =)

[clairernovotny]

Thanks for this. It was done a different way.