Update EC2MetadataUtilServer to only accept localhost address

Author: zoewangg

core/src/it/java/software/amazon/awssdk/core/util/EC2MetadataUtilsIntegrationTest.java

@@ -29,7 +29,7 @@ public class EC2MetadataUtilsIntegrationTest {
 
     @BeforeClass
     public static void setUp() throws IOException {
-        SERVER = new EC2MetadataUtilsServer("localhost", 0);
+        SERVER = new EC2MetadataUtilsServer( 0);
         SERVER.start();
 
         System.setProperty(AwsSystemSetting.AWS_EC2_METADATA_SERVICE_ENDPOINT.property(),

core/src/test/java/software/amazon/awssdk/core/regions/providers/InstanceProfileRegionProviderTest.java

@@ -47,7 +47,7 @@ public static class MetadataServiceRunningTest {
 
         @BeforeClass
         public static void setupFixture() throws IOException {
-            server = new EC2MetadataUtilsServer("localhost", 0);
+            server = new EC2MetadataUtilsServer(0);
             server.start();
 
             System.setProperty(AwsSystemSetting.AWS_EC2_METADATA_SERVICE_ENDPOINT.property(),

core/src/test/java/software/amazon/awssdk/core/util/EC2MetadataUtilsServer.java

@@ -33,9 +33,9 @@ public class EC2MetadataUtilsServer {
 
     private ServerSocket server;
 
-    public EC2MetadataUtilsServer(String address, int port)
+    public EC2MetadataUtilsServer(int port)
             throws UnknownHostException, IOException {
-        server = new ServerSocket(port, 1, InetAddress.getByName(address));
+        server = new ServerSocket(port, 1, InetAddress.getLoopbackAddress());
     }
 
     public void start()