Fix DiscoveryEc2AvailabilityZoneAttributeNoImdsIT (#118821)

This test asserts that no AZ attribute is set, assuming that the current
AZ is unavailable, but in fact that's not true when running these tests
in EC2. With this commit we override the IMDS endpoint address to one
that definitely does not exist.

Relates #118675 Closes #118564

Author: DaveCTurner

plugins/discovery-ec2/src/javaRestTest/java/org/elasticsearch/discovery/ec2/DiscoveryEc2AvailabilityZoneAttributeNoImdsIT.java

@@ -9,30 +9,24 @@
 
 package org.elasticsearch.discovery.ec2;
 
-import com.amazonaws.util.EC2MetadataUtils;
-
 import org.elasticsearch.client.Request;
 import org.elasticsearch.test.cluster.ElasticsearchCluster;
-import org.elasticsearch.test.rest.ESRestTestCase;
 import org.junit.ClassRule;
 
 import java.io.IOException;
 
-public class DiscoveryEc2AvailabilityZoneAttributeNoImdsIT extends ESRestTestCase {
+public class DiscoveryEc2AvailabilityZoneAttributeNoImdsIT extends DiscoveryEc2AvailabilityZoneAttributeTestCase {
     @ClassRule
-    public static ElasticsearchCluster cluster = ElasticsearchCluster.local()
-        .plugin("discovery-ec2")
-        .setting(AwsEc2Service.AUTO_ATTRIBUTE_SETTING.getKey(), "true")
-        .build();
+    // use an address which definitely isn't running an IMDS, just in case we're running these tests in EC2
+    public static ElasticsearchCluster cluster = DiscoveryEc2AvailabilityZoneAttributeTestCase.buildCluster(() -> "http://127.0.0.1:1");
 
     @Override
     protected String getTestRestCluster() {
         return cluster.getHttpAddresses();
     }
 
+    @Override // the base class asserts that the attribute is set, but we don't want that here
     public void testAvailabilityZoneAttribute() throws IOException {
-        assumeTrue("test only in non-AWS environment", EC2MetadataUtils.getInstanceId() == null);
-
         final var nodesInfoResponse = assertOKAndCreateObjectPath(client().performRequest(new Request("GET", "/_nodes/_all/_none")));
         for (final var nodeId : nodesInfoResponse.evaluateMapKeys("nodes")) {
             assertNull(nodesInfoResponse.evaluateExact("nodes", nodeId, "attributes", "aws_availability_zone"));