ElasticReindexIT: Add tests against Elasticsearch version 5

Bug: Issue 6094
Change-Id: I324d099ee4cc484fcdfea8679e38cc2d3d2b5905

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/pgm/ElasticReindexIT.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.acceptance.pgm;
 
 import com.google.gerrit.acceptance.NoHttpd;
+import com.google.gerrit.elasticsearch.ElasticVersion;
 import com.google.gerrit.elasticsearch.testing.ElasticContainer;
 import com.google.gerrit.elasticsearch.testing.ElasticTestUtils;
 import com.google.gerrit.elasticsearch.testing.ElasticTestUtils.ElasticNodeInfo;
@@ -28,11 +29,10 @@
 public class ElasticReindexIT extends AbstractReindexTests {
   private static ElasticContainer<?> container;
 
-  @ConfigSuite.Default
-  public static Config elasticsearch() {
+  private static Config getConfig(ElasticVersion version) {
     ElasticNodeInfo elasticNodeInfo;
     try {
-      container = ElasticContainer.createAndStart();
+      container = ElasticContainer.createAndStart(version);
       elasticNodeInfo = new ElasticNodeInfo(container.getHttpHost().getPort());
     } catch (Throwable t) {
       return null;
@@ -43,6 +43,16 @@ public static Config elasticsearch() {
     return cfg;
   }
 
+  @ConfigSuite.Default
+  public static Config elasticsearchV2() {
+    return getConfig(ElasticVersion.V2_4);
+  }
+
+  @ConfigSuite.Config
+  public static Config elasticsearchV5() {
+    return getConfig(ElasticVersion.V5_6);
+  }
+
   @Override
   public void configureIndex(Injector injector) throws Exception {
     ElasticTestUtils.createAllIndexes(injector);