Check if not null in the constructor

Change-Id: I5e73660004e5bb8e9e3c5ba6b02d1070ee977c22

@@ -757,7 +757,7 @@ public class IntentManager
         private int installAttempt;
 
         public IntentInstallMonitor(IntentOperations ops) {
-            this.ops = ops;
+            this.ops = checkNotNull(ops);
             resetTimeoutLimit();
         }