Update FeatureGatedAsyncActionFilter.cs (#260)

use `context.HttpContext.RequestServices` directly

Co-authored-by: Zhiyuan Liang <141655842+zhiyuanliang-ms@users.noreply.github.com>

src/Microsoft.FeatureManagement.AspNetCore/FeatureGatedAsyncActionFilter.cs

@@ -32,9 +32,7 @@ public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionE
 
             if (await featureManager.IsEnabledAsync(FeatureName).ConfigureAwait(false))
             {
-                IServiceProvider serviceProvider = context.HttpContext.RequestServices.GetRequiredService<IServiceProvider>();
-
-                IAsyncActionFilter filter = ActivatorUtilities.CreateInstance<T>(serviceProvider);
+                IAsyncActionFilter filter = ActivatorUtilities.CreateInstance<T>(context.HttpContext.RequestServices);
 
                 await filter.OnActionExecutionAsync(context, next).ConfigureAwait(false);
             }