Use XML to Linq

Author: amanda-tarafa

Src/Support/IntegrationTests/ExternalAccountCredentialTests.cs

@@ -22,9 +22,10 @@ limitations under the License.
 using Google.Apis.Storage.v1.Data;
 using IntegrationTests.Utils;
 using System;
+using System.Linq;
 using System.Net.Http;
 using System.Threading.Tasks;
-using System.Xml;
+using System.Xml.Linq;
 using Xunit;
 
 namespace IntegrationTests
@@ -76,8 +77,7 @@ public async Task AwsCredentials()
                 HttpResponseMessage response = await httpClient.GetAsync(assumeRoleUrl);
                 content = await response.Content.ReadAsStringAsync();
             }
-            XmlDocument awsCredentialXml = new XmlDocument();
-            awsCredentialXml.LoadXml(content);
+            XElement awsCredentialXml = XElement.Parse(content);
 
             // We store AWS credentials in environment variables to mimic an AWS environment.
             Environment.SetEnvironmentVariable("AWS_ACCESS_KEY_ID", AwsCredentialValue("AccessKeyId"));
@@ -109,7 +109,8 @@ public async Task AwsCredentials()
             // A final sanity-check.
             Assert.NotNull(buckets.Items);
 
-            string AwsCredentialValue(string tagName) => awsCredentialXml.GetElementsByTagName(tagName)[0].InnerText;
+            string AwsCredentialValue(string tagName) =>
+                awsCredentialXml.Descendants().Where(element => element.Name.LocalName == tagName).Single().Value;
         }
     }
 }