DOTNET-202: Fix .NET Core proxy support

Src/StackifyLib/Utils/HttpClient.cs

@@ -85,9 +85,7 @@ public bool IsClientError()
 
         static HttpClient()
         {
-#if NETFULL
             LoadWebProxyConfig();
-#endif
         }
 
         public HttpClient(string apiKey, string apiUrl)

test/StackifyLib.UnitTests/Utils/HttpClient_Loading_Tests.cs

@@ -0,0 +1,55 @@
+// Copyright (c) 2024-2025 BMC Software, Inc.
+// Copyright (c) 2021-2024 Netreo
+// Copyright (c) 2019 Stackify
+using Moq;
+using StackifyLib.Models;
+using StackifyLib.Utils;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Reflection;
+using System.Security.Policy;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace StackifyLib.UnitTests.Utils
+{
+    public class HttpClient_Loading_Tests : IDisposable
+    {
+        private readonly HttpClient _httpClient;
+
+        public HttpClient_Loading_Tests()
+        {
+            // Store original values to restore after tests
+            Config.ProxyServer = "http://testuser:[email protected]:8881";
+            _httpClient = new HttpClient("test-api-key", "https://test.api.com/");
+            HttpClient.IsUnitTest = true;
+        }
+
+        public void Dispose()
+        {
+            HttpClient.IsUnitTest = false;
+        }
+
+        [Fact(Skip = "This test should be run explicitly (due to static loading nature of HttpClient)")]
+        public void LoadWebProxyConfig_DefaultBehavior()
+        {
+            // Arrange - Mock the Config.Get method to return true for UseDefaultCredentials
+            try
+            {
+                var customProxy = HttpClient.CustomWebProxy as WebProxy;
+                Assert.NotNull(customProxy);
+
+                // Note: We can't easily test UseDefaultCredentials without mocking Config.Get
+                // This test verifies the method runs without error when proxy is configured
+                Assert.Equal("docker-hyperv.local", customProxy.Address.Host);
+                Assert.Equal(8881, customProxy.Address.Port);
+            }
+            finally
+            {
+            }
+        }
+    }
+}