add SuppressWarnings

Author: guyinyou

store/src/main/java/org/apache/rocketmq/store/timer/TimerMetrics.java

@@ -56,6 +56,7 @@ public class TimerMetrics extends ConfigManager {
 
     private final ConcurrentMap<Integer, Metric> timingDistribution = new ConcurrentHashMap<>(1024);
 
+    @SuppressWarnings("DoubleBraceInitialization")
     public List<Integer> timerDist = new ArrayList<Integer>() {{
             add(5);
             add(60);