Refactored Kafka Application to simplify dependencies

1. Fixed a Bug in KafkaProducer. Without this fix the App will not send data in GPB format.
2. Added two new services - KafkaProducerService and KafkaConfigService.
3. Fixed a TODO in the register API to return Kafka server information.
4. Removed the use of LeadershipService and ClusterService, since we are not ready for clustering yet.

Change-Id: If20ef5238bb4629af0c6769129494eb44abf1d3c
diff --git a/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/impl/KafkaStorageManager.java b/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/impl/KafkaStorageManager.java
index 64af4e8..6f61f6a 100644
--- a/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/impl/KafkaStorageManager.java
+++ b/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/impl/KafkaStorageManager.java
@@ -31,7 +31,7 @@
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
-@Component(immediate = true)
+@Component(immediate = false)
 public class KafkaStorageManager implements KafkaEventStorageService {
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)