Test AppConfigAWSCredentials case

Author: DmitryLukyanov

tests/MongoDB.Driver.Tests/Communication/Security/AwsAuthenticationTests.cs

@@ -75,6 +75,13 @@ public void AwsSdk_should_support_all_required_callbacks()
 
             // Attempt 1
             AWSCredentials credentials = null;
+            if (Type.GetType("Amazon.Runtime.AppConfigAWSCredentials", throwOnError: false) != null)
+            {
+                var appConfigAWSCredentialsException = Record.Exception(() => RunTestCase());
+                // app.config/web.config case based on ConfigurationManager. This is not configured for this test
+                appConfigAWSCredentialsException.Message.Should().Contain("The app.config/web.config files for the application did not contain credential information");
+            }
+
             var exception = Record.Exception(() => RunTestCase());
             if (Environment.GetEnvironmentVariable("AWS_WEB_IDENTITY_TOKEN_FILE") != null)
             {