Elasticsearch V6: Add include_type_name to index requests

Before this change, there were warnings in Eclipse about the lack of
explicitly specifying that parameter in such get-indices HEAD requests.

Bug: Issue 10884
Change-Id: I02fb4b445e91ee6f3c9aa3f6a7a4b8e2327e8967
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index 2e30e59..08a8763 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -149,7 +149,7 @@
   @Override
   public void deleteAll() throws IOException {
     // Delete the index, if it exists.
-    String endpoint = indexName + client.adapter().indicesExistParam();
+    String endpoint = indexName + client.adapter().indicesExistParams();
     Response response = performRequest("HEAD", endpoint);
     int statusCode = response.getStatusLine().getStatusCode();
     if (statusCode == HttpStatus.SC_OK) {
diff --git a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
index 329913b..026f09a 100644
--- a/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
+++ b/gerrit-elasticsearch/src/main/java/com/google/gerrit/elasticsearch/ElasticQueryAdapter.java
@@ -19,13 +19,16 @@
 public class ElasticQueryAdapter {
   static final String V6_TYPE = "_doc";
 
+  private static final String INCLUDE_TYPE = "include_type_name=true";
+  private static final String INDICES = "?allow_no_indices=false";
+
   private final boolean ignoreUnmapped;
   private final boolean useV5Type;
   private final boolean useV6Type;
   private final boolean omitType;
 
   private final String searchFilteringName;
-  private final String indicesExistParam;
+  private final String indicesExistParams;
   private final String exactFieldType;
   private final String stringFieldType;
   private final String indexProperty;
@@ -39,11 +42,11 @@
     this.omitType = version.isV7OrLater();
     this.versionDiscoveryUrl = version.isV6OrLater() ? "/%s*" : "/%s*/_aliases";
     this.searchFilteringName = "_source";
-    this.indicesExistParam = "?allow_no_indices=false";
+    this.indicesExistParams = version.isV6() ? INDICES + "&" + INCLUDE_TYPE : INDICES;
     this.exactFieldType = "keyword";
     this.stringFieldType = "text";
     this.indexProperty = "true";
-    this.includeTypeNameParam = version.isV6() ? "?include_type_name=true" : "";
+    this.includeTypeNameParam = version.isV6() ? "?" + INCLUDE_TYPE : "";
   }
 
   void setIgnoreUnmapped(JsonObject properties) {
@@ -62,8 +65,8 @@
     return searchFilteringName;
   }
 
-  String indicesExistParam() {
-    return indicesExistParam;
+  String indicesExistParams() {
+    return indicesExistParams;
   }
 
   String exactFieldType() {