Fix ReadyLocalTransactionSerializer

Fix ReadyLocalTransactionSerializer

The following exception was seen in the field:

2017-12-20 19:37:05,507 | ERROR | ult-dispatcher-2 | Remoting                         | 174 - com.typesafe.akka.slf4j - 2.4.7 | java.lang.ClassNotFoundException: org.opendaylight.controller.cluster.datastore.messages.BatchedModifications
org.apache.commons.lang3.SerializationException: java.lang.ClassNotFoundException: org.opendaylight.controller.cluster.datastore.messages.BatchedModifications
        at org.apache.commons.lang3.SerializationUtils.deserialize(SerializationUtils.java:229)
        at org.apache.commons.lang3.SerializationUtils.deserialize(SerializationUtils.java:267)
        at org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransactionSerializer.fromBinaryJava(ReadyLocalTransactionSerializer.java:49)
        at akka.serialization.JSerializer.fromBinary(Serializer.scala:177)
        at akka.serialization.Serialization$$anonfun$deserialize$2.apply(Serialization.scala:124)
        at scala.util.Try$.apply(Try.scala:192)
        at akka.serialization.Serialization.deserialize(Serialization.scala:114)
        at akka.remote.serialization.MessageContainerSerializer.fromBinary(MessageContainerSerializer.scala:80)
        at akka.serialization.Serialization$$anonfun$deserialize$2.apply(Serialization.scala:124)
        at scala.util.Try$.apply(Try.scala:192)
        at akka.serialization.Serialization.deserialize(Serialization.scala:114)
        at akka.remote.MessageSerializer$.deserialize(MessageSerializer.scala:24)
        at akka.remote.DefaultMessageDispatcher.payload$lzycompute$1(Endpoint.scala:60)
        at akka.remote.DefaultMessageDispatcher.payload$1(Endpoint.scala:60)
        at akka.remote.DefaultMessageDispatcher.dispatch(Endpoint.scala:78)
        at akka.remote.EndpointReader$$anonfun$receive$2.applyOrElse(Endpoint.scala:978)
        at akka.actor.Actor$class.aroundReceive(Actor.scala:484)
        at akka.remote.EndpointActor.aroundReceive(Endpoint.scala:447)
        at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
        at akka.actor.ActorCell.invoke(ActorCell.scala:495)
        at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
        at akka.dispatch.Mailbox.run(Mailbox.scala:224)
        at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
        at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
        at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
        at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
        at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.lang.ClassNotFoundException: org.opendaylight.controller.cluster.datastore.messages.BatchedModifications
        at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:501)
        at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:421)
        at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:412)
        at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:348)
        at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:683)
        at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1863)
        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1746)
        at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2037)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1568)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:428)
        at org.apache.commons.lang3.SerializationUtils.deserialize(SerializationUtils.java:223)
        ... 26 more

As it turns out, ReadyLocalTransactionSerializer is not following JSerializer
documentation recommendations of loading classes via ExtendedActorSystem.

Change-Id: Idef62f8c7a50d607ef152083693fac63c7e92447
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
(cherry picked from commit c64b1e26da272928abe57648757d578c2ac33869)