Adding trace logging to IntentManger

Change-Id: I6cd55521484f52223de5cec563f13b61d97ae4a9
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
index 3c73851..16404e3 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentManager.java
@@ -501,6 +501,14 @@
             }
         });
 
+        if (log.isTraceEnabled()) {
+            log.trace("applying intent {} -> {} with {} rules: {}",
+                      toUninstall.isPresent() ? toUninstall.get().key() : "<empty>",
+                      toInstall.isPresent() ? toInstall.get().key() : "<empty>",
+                      operations.stages().stream().mapToLong(i -> i.size()).sum(),
+                      operations.stages());
+        }
+
         flowRuleService.apply(operations);
     }