Utilize StandardCharsets

Closes gh-10972

spring-boot-samples/spring-boot-sample-undertow/src/test/java/sample/undertow/SampleUndertowApplicationTests.java

@@ -18,6 +18,7 @@ package sample.undertow;
 
 import java.io.ByteArrayInputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.zip.GZIPInputStream;
 
 import org.junit.Test;
@@ -73,7 +74,7 @@ public class SampleUndertowApplicationTests {
 
 		try (GZIPInputStream inflater = new GZIPInputStream(
 				new ByteArrayInputStream(entity.getBody()))) {
-			assertThat(StreamUtils.copyToString(inflater, Charset.forName("UTF-8")))
+			assertThat(StreamUtils.copyToString(inflater, StandardCharsets.UTF_8))
 					.isEqualTo("Hello World");
 		}
 	}