Filter indices stats for translog

Added the missing call in the RestAction, closes #8262

docs/reference/indices/stats.asciidoc

@@ -47,6 +47,7 @@ specified as well in the URI. Those stats can be any of:
 `refresh`::     Refresh statistics.
 `suggest`::     Suggest statistics.
 `warmer`::      Warmer statistics.
+`translog`::    Translog statistics.
 
 Some statistics allow per field granularity which accepts a list
 comma-separated list of included fields. By default all fields are included:

src/main/java/org/elasticsearch/rest/action/admin/indices/stats/RestIndicesStatsAction.java

@@ -82,6 +82,7 @@ public class RestIndicesStatsAction extends BaseRestHandler {
             indicesStatsRequest.suggest(metrics.contains("suggest"));
             indicesStatsRequest.queryCache(metrics.contains("query_cache"));
             indicesStatsRequest.recovery(metrics.contains("recovery"));
+            indicesStatsRequest.translog(metrics.contains("translog"));
         }
 
         if (request.hasParam("groups")) {