[ONOS-4520] Move Protobuf to ONOS model conversion util protobuf bundle.

Change-Id: I0fbfd750d569cb5da6dd29af5aa77d19d6f29494
diff --git a/incubator/protobuf/src/main/java/org/onosproject/incubator/protobuf/net/package-info.java b/incubator/protobuf/src/main/java/org/onosproject/incubator/protobuf/net/package-info.java
new file mode 100644
index 0000000..aa17131
--- /dev/null
+++ b/incubator/protobuf/src/main/java/org/onosproject/incubator/protobuf/net/package-info.java
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * Utilities to handle ProtoBuf version of ONOS network models.
+ */
+package org.onosproject.incubator.protobuf.net;