[test] Avoid running the NoImds test on AWS

Disabled the NoImds test on AWS EC2 instance where it fails because the
AWS metadata are available, which is not expected by this test.

Author: jozala

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

@@ -9,6 +9,8 @@
 
 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;
@@ -29,6 +31,8 @@ protected String getTestRestCluster() {
     }
 
     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"));