Add support for Elasticsearch 6.4.0

According to the release notes [1] there are several breaking changes,
but none of them seem to affect Gerrit's integration.

Update the version manager and adapter to recognize 6.4.* as a supported
version, and modify the test container to use 6.4.0 for the V6 tests.

Update the reindex and ssh index tests to also test against 6.4.0.

[1] https://www.elastic.co/guide/en/elasticsearch/reference/current/release-notes-6.4.0.html

Bug: Issue 9670
Change-Id: If0d16df1a719d45aad9c56409e14c8fcf3945bd5

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

@@ -58,6 +58,11 @@ public class ElasticReindexIT extends AbstractReindexTests {
     return getConfig(ElasticVersion.V6_3);
   }
 
+  @ConfigSuite.Config
+  public static Config elasticsearchV6_4() {
+    return getConfig(ElasticVersion.V6_4);
+  }
+
   @Override
   public void configureIndex(Injector injector) throws Exception {
     ElasticTestUtils.createAllIndexes(injector);

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/ssh/ElasticIndexIT.java

@@ -55,6 +55,11 @@ public class ElasticIndexIT extends AbstractIndexTests {
     return getConfig(ElasticVersion.V6_3);
   }
 
+  @ConfigSuite.Config
+  public static Config elasticsearchV6_4() {
+    return getConfig(ElasticVersion.V6_4);
+  }
+
   @Override
   public void configureIndex(Injector injector) throws Exception {
     ElasticTestUtils.createAllIndexes(injector);

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java

@@ -38,6 +38,7 @@ public class ElasticQueryAdapter {
       case V5_6:
       case V6_2:
       case V6_3:
+      case V6_4:
         this.searchFilteringName = "_source";
         this.indicesExistParam = "?allow_no_indices=false";
         this.exactFieldType = "keyword";

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticVersion.java

@@ -21,7 +21,8 @@ public enum ElasticVersion {
   V2_4("2.4.*"),
   V5_6("5.6.*"),
   V6_2("6.2.*"),
-  V6_3("6.3.*");
+  V6_3("6.3.*"),
+  V6_4("6.4.*");
 
   private final String version;
   private final Pattern pattern;

gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/testing/ElasticContainer.java

@@ -51,6 +51,8 @@ public class ElasticContainer<SELF extends ElasticContainer<SELF>> extends Gener
         return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.2.4";
       case V6_3:
         return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.3.2";
+      case V6_4:
+        return "docker.elastic.co/elasticsearch/elasticsearch-oss:6.4.0";
     }
     throw new IllegalStateException("No tests for version: " + version.name());
   }

gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticV6QueryAccountsTest.java

@@ -36,7 +36,7 @@ public class ElasticV6QueryAccountsTest extends AbstractQueryAccountsTest {
       return;
     }
 
-    container = ElasticContainer.createAndStart(ElasticVersion.V6_3);
+    container = ElasticContainer.createAndStart(ElasticVersion.V6_4);
     nodeInfo = new ElasticNodeInfo(container.getHttpHost().getPort());
   }
 

gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticV6QueryChangesTest.java

@@ -37,7 +37,7 @@ public class ElasticV6QueryChangesTest extends AbstractQueryChangesTest {
       return;
     }
 
-    container = ElasticContainer.createAndStart(ElasticVersion.V6_3);
+    container = ElasticContainer.createAndStart(ElasticVersion.V6_4);
     nodeInfo = new ElasticNodeInfo(container.getHttpHost().getPort());
   }
 

gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticV6QueryGroupsTest.java

@@ -36,7 +36,7 @@ public class ElasticV6QueryGroupsTest extends AbstractQueryGroupsTest {
       return;
     }
 
-    container = ElasticContainer.createAndStart(ElasticVersion.V6_3);
+    container = ElasticContainer.createAndStart(ElasticVersion.V6_4);
     nodeInfo = new ElasticNodeInfo(container.getHttpHost().getPort());
   }
 

gerrit-elasticsearch/src/test/java/com/google/gerrit/elasticsearch/ElasticVersionTest.java

@@ -37,6 +37,9 @@ public class ElasticVersionTest {
 
     assertThat(ElasticVersion.forVersion("6.3.0")).isEqualTo(ElasticVersion.V6_3);
     assertThat(ElasticVersion.forVersion("6.3.1")).isEqualTo(ElasticVersion.V6_3);
+
+    assertThat(ElasticVersion.forVersion("6.4.0")).isEqualTo(ElasticVersion.V6_4);
+    assertThat(ElasticVersion.forVersion("6.4.1")).isEqualTo(ElasticVersion.V6_4);
   }
 
   @Test