Turn on error for the EmptyBlockTag bug pattern and fix related problems

Change-Id: Ie29dfc15cb26121d1cebf031058826c6bffaa892

java/com/google/gerrit/elasticsearch/ElasticVersion.java

diff --git a/java/com/google/gerrit/elasticsearch/ElasticVersion.java b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
index c6400df..b5bf44b 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticVersion.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticVersion.java
@@ -45,7 +45,6 @@
    *
    * @param version for which to return an ElasticVersion
    * @return the corresponding ElasticVersion if supported
-   * @throws UnsupportedVersion
    */
   public static ElasticVersion forVersion(String version) {
     for (ElasticVersion value : ElasticVersion.values()) {