ElasticV6QueryChangesTest: Align with changes done in V7

- Fix FutureReturnValueIgnored (I7d119d05f)
- Replace GerritBaseTests#sanitizedMethodName with a TestRule
  (Ia3d8487f9)

Change-Id: Id4155394ac203c1e53e88132ad133be9fc0fad9d

javatests/com/google/gerrit/elasticsearch/ElasticV6QueryChangesTest.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.elasticsearch;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+
 import com.google.gerrit.elasticsearch.ElasticTestUtils.ElasticNodeInfo;
 import com.google.gerrit.server.query.change.AbstractQueryChangesTest;
 import com.google.gerrit.testing.ConfigSuite;
@@ -62,18 +64,21 @@ public class ElasticV6QueryChangesTest extends AbstractQueryChangesTest {
     }
   }
 
-  @After
-  public void closeIndex() {
-    client.execute(
-        new HttpPost(
-            String.format(
-                "http://localhost:%d/%s*/_close", nodeInfo.port, getSanitizedMethodName())),
-        HttpClientContext.create(),
-        null);
-  }
-
   @Rule public final GerritTestName testName = new GerritTestName();
 
+  @After
+  public void closeIndex() throws Exception {
+    client
+        .execute(
+            new HttpPost(
+                String.format(
+                    "http://localhost:%d/%s*/_close",
+                    nodeInfo.port, testName.getSanitizedMethodName())),
+            HttpClientContext.create(),
+            null)
+        .get(5, MINUTES);
+  }
+
   @Override
   protected void initAfterLifecycleStart() throws Exception {
     super.initAfterLifecycleStart();