[ONOS-4520] Separate model messages from service messages in ProtoBuf IDL.

- move ProtoBuf generated code in a package similar to ONOS models.

Change-Id: I5deb591094c2b8af2b22041da935567fc8dacd87
diff --git a/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/DeviceProviderServiceClientProxy.java b/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/DeviceProviderServiceClientProxy.java
index 83bd44f..185e094 100644
--- a/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/DeviceProviderServiceClientProxy.java
+++ b/incubator/rpc-grpc/src/main/java/org/onosproject/incubator/rpc/grpc/DeviceProviderServiceClientProxy.java
@@ -24,13 +24,13 @@
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import org.onosproject.grpc.Device.DeviceProviderMsg;
-import org.onosproject.grpc.Device.DeviceProviderServiceMsg;
-import org.onosproject.grpc.Device.IsReachableRequest;
-import org.onosproject.grpc.Device.RoleChanged;
-import org.onosproject.grpc.Device.TriggerProbe;
-import org.onosproject.grpc.DeviceProviderRegistryRpcGrpc;
-import org.onosproject.grpc.DeviceProviderRegistryRpcGrpc.DeviceProviderRegistryRpcStub;
+import org.onosproject.grpc.net.device.DeviceProviderRegistryRpcGrpc;
+import org.onosproject.grpc.net.device.DeviceProviderRegistryRpcGrpc.DeviceProviderRegistryRpcStub;
+import org.onosproject.grpc.net.device.DeviceService.DeviceProviderMsg;
+import org.onosproject.grpc.net.device.DeviceService.DeviceProviderServiceMsg;
+import org.onosproject.grpc.net.device.DeviceService.IsReachableRequest;
+import org.onosproject.grpc.net.device.DeviceService.RoleChanged;
+import org.onosproject.grpc.net.device.DeviceService.TriggerProbe;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.MastershipRole;
 import org.onosproject.net.device.DeviceDescription;
@@ -112,7 +112,7 @@
         checkValidity();
 
         DeviceProviderServiceMsg.Builder builder = DeviceProviderServiceMsg.newBuilder();
-        List<org.onosproject.grpc.Port.PortDescription> portDescs =
+        List<org.onosproject.grpc.net.Port.PortDescription> portDescs =
                 portDescriptions.stream()
                     .map(GrpcDeviceUtils::translate)
                     .collect(toList());
@@ -160,7 +160,7 @@
         checkValidity();
 
         DeviceProviderServiceMsg.Builder builder = DeviceProviderServiceMsg.newBuilder();
-        List<org.onosproject.grpc.Port.PortStatistics> portStats =
+        List<org.onosproject.grpc.net.Port.PortStatistics> portStats =
                 portStatistics.stream()
                     .map(GrpcDeviceUtils::translate)
                     .collect(toList());