Improve Executors related logging behavior

- Specify Logger for the Executor
- Use Executor#execute instead of ExecutorService#submit for
  fire and forget type of usage.
   Note: submit() will swallow thrown Exception

Change-Id: I507b841dc3feedf4ad20a746c304518d68fb846a
diff --git a/core/store/dist/src/main/java/org/onosproject/store/mastership/impl/ConsistentDeviceMastershipStore.java b/core/store/dist/src/main/java/org/onosproject/store/mastership/impl/ConsistentDeviceMastershipStore.java
index bd5eea5..01f3cb2 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/mastership/impl/ConsistentDeviceMastershipStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/mastership/impl/ConsistentDeviceMastershipStore.java
@@ -123,10 +123,10 @@
     public void activate() {
         messageHandlingExecutor =
                 Executors.newSingleThreadExecutor(
-                        groupedThreads("onos/store/device/mastership", "message-handler"));
+                        groupedThreads("onos/store/device/mastership", "message-handler", log));
         transferExecutor =
                 Executors.newSingleThreadScheduledExecutor(
-                        groupedThreads("onos/store/device/mastership", "mastership-transfer-executor"));
+                        groupedThreads("onos/store/device/mastership", "mastership-transfer-executor", log));
         clusterCommunicator.addSubscriber(ROLE_RELINQUISH_SUBJECT,
                 SERIALIZER::decode,
                 this::relinquishLocalRole,