[dotnet] Stabilize ShouldTimeoutIfAPageTakesTooLongToRefresh test (#16880)

Author: nvborisenko

dotnet/test/common/PageLoadingTest.cs

@@ -376,16 +376,14 @@ public void ShouldTimeoutIfAPageTakesTooLongToLoadAfterClick()
     public void ShouldTimeoutIfAPageTakesTooLongToRefresh()
     {
         // Get the sleeping servlet with a pause of 5 seconds
-        long pageLoadTimeout = 2;
-        long pageLoadTimeBuffer = 0;
-        string slowLoadingPageUrl = EnvironmentManager.Instance.UrlBuilder.WhereIs("sleep?time=" + (pageLoadTimeout + pageLoadTimeBuffer));
+        string slowLoadingPageUrl = EnvironmentManager.Instance.UrlBuilder.WhereIs("sleep?time=5");
         driver.Url = slowLoadingPageUrl;
 
         driver.Manage().Timeouts().PageLoad = TimeSpan.FromSeconds(2);
 
         try
         {
-            AssertPageLoadTimeoutIsEnforced(() => driver.Navigate().Refresh(), 2, 4);
+            AssertPageLoadTimeoutIsEnforced(driver.Navigate().Refresh, 2, 4);
         }
         finally
         {