Fixes [ONOS-5742]

Changes:
- Fixes the problem of "missing" installation contexts
due synchronization problem on IntentInstaller;

Change-Id: Ia8f9fa27f4d23ad390d73fe40739490836af178f
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentInstaller.java b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentInstaller.java
index 631151b..49433af 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/IntentInstaller.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/IntentInstaller.java
@@ -433,11 +433,11 @@
 
         @Override
         void apply() {
-            contexts.forEach(objectiveContext -> {
-                pendingContexts.add(objectiveContext);
+            pendingContexts.addAll(contexts);
+            contexts.forEach(objectiveContext ->
                 flowObjectiveService.apply(objectiveContext.deviceId,
-                                           objectiveContext.objective);
-            });
+                                           objectiveContext.objective)
+            );
         }
 
         @Override