fix: Virtual flow rule and packet store

Changes.
1. Simple Packet store is declared as OSGi component
2. some description is added

Change-Id: Iaffa6786bbca5b967926b19183f45b723b8ab211
diff --git a/incubator/store/src/main/java/org/onosproject/incubator/store/virtual/impl/SimpleVirtualFlowRuleStore.java b/incubator/store/src/main/java/org/onosproject/incubator/store/virtual/impl/SimpleVirtualFlowRuleStore.java
index 412ffd1..5f71b57 100644
--- a/incubator/store/src/main/java/org/onosproject/incubator/store/virtual/impl/SimpleVirtualFlowRuleStore.java
+++ b/incubator/store/src/main/java/org/onosproject/incubator/store/virtual/impl/SimpleVirtualFlowRuleStore.java
@@ -68,10 +68,11 @@
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
- * Manages inventory of virtual flow rules using trivial in-memory implementation.
+ * Implementation of the virtual network flow rule store to manage inventory of
+ * virtual flow rules using trivial in-memory implementation.
  */
-
 //TODO: support distributed flowrule store for virtual networks
+
 @Component(immediate = true)
 @Service
 public class SimpleVirtualFlowRuleStore