Microsoft.FeatureManagement Updates

The packages associated with this release are

Microsoft.FeatureManagement

The feature flag telemetry pipeline is now integrated with .NET Acitivity instrumentation. Feature manager now has an AcitvitySource called "Microsoft.FeatureManagement". If telemetry is enabled for a feature flag, whenever the feature flag is evaluated, feature manager will start an Activity and add an ActivityEvent with tags containing feature evaluation information. #455

If you were using earlier preview versions of this package and configuration files to define variant feature flags, they are no longer supported in the .NET Feature Management schema. Instead, please use the Microsoft Feature Management schema to define variant feature flags. #421.
AddTelemetryPublisher API and ITelemetryPublisher interface were removed. The feature flag telemetry pipeline is now integrated with .NET Acitivity instrumentation. #455

Introduced a new API AddApplicationInsightsTelemetryPublisher to register a feature flag telemetry publisher for Application Insights. #455

builder.Services.AddFeatureManagement()
                .WithTargeting()
                .AddApplicationInsightsTelemetryPublisher();

The TargetingTelemetryInitializer type has been moved to this package from the now-deprecated Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore package. This change simplifies the utilization of feature flag telemetry.
The type ApplicationInsightsTelemetryPublisher has been removed as its functionality has been replaced with the new API AddApplicationInsightsTelemetryPublisher for publishing feature flag telemetry to Application Insights. #455