Avoid repacking the same map

Author: joegallo

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/authz/accesscontrol/DocumentSubsetBitsetCache.java

@@ -38,7 +38,6 @@
 
 import java.io.Closeable;
 import java.io.IOException;
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -316,7 +315,7 @@ public Map<String, Object> usageStats() {
         stats.put("evictions", cacheStats.getEvictions());
         stats.put("hits_time_in_millis", TimeValue.nsecToMSec(hitsTimeInNanos.sum()));
         stats.put("misses_time_in_millis", TimeValue.nsecToMSec(missesTimeInNanos.sum()));
-        return Collections.unmodifiableMap(stats);
+        return stats;
     }
 
     private static final class BitsetCacheKey {

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authz/store/CompositeRolesStore.java

@@ -671,9 +671,7 @@ Iterable<ProjectScoped<RoleKey>> cachedRoles() {
     }
 
     public Map<String, Object> usageStatsWithJustDls() {
-        // LinkedHashMap for ordering in transport.
-        // if adding properties consider consistent ordering for human-readability of JSON.
-        return Map.of("dls", Map.of("bit_set_cache", new LinkedHashMap<>(dlsBitsetCache.usageStats())));
+        return Map.of("dls", Map.of("bit_set_cache", dlsBitsetCache.usageStats()));
     }
 
     public void usageStats(ActionListener<Map<String, Object>> listener) {