Use lambda expression to reduce lines

Change-Id: Ie8994f79acc6b2f4204f62aca1fe6112baf578cd
diff --git a/core/net/src/main/java/org/onosproject/net/flow/impl/FlowRuleManager.java b/core/net/src/main/java/org/onosproject/net/flow/impl/FlowRuleManager.java
index d38f4fe..441219a 100644
--- a/core/net/src/main/java/org/onosproject/net/flow/impl/FlowRuleManager.java
+++ b/core/net/src/main/java/org/onosproject/net/flow/impl/FlowRuleManager.java
@@ -559,12 +559,7 @@
                 final FlowRuleBatchOperation b = new FlowRuleBatchOperation(perDeviceBatches.get(deviceId),
                                                deviceId, id);
                 pendingFlowOperations.put(id, this);
-                deviceInstallers.submit(new Runnable() {
-                    @Override
-                    public void run() {
-                        store.storeBatch(b);
-                    }
-                });
+                deviceInstallers.submit(() -> store.storeBatch(b));
             }
         }