Use voltha-protos version 4.0.2
Bump major version of voltha-lib-go to 4.0.0 as this change results
in incompatible API version compared to previous version

Change-Id: I1def58361fb1d85f07d6948ebf1ffb7a92eb0d4c
diff --git a/pkg/flows/flow_utils.go b/pkg/flows/flow_utils.go
index 9b800bf..98fad49 100644
--- a/pkg/flows/flow_utils.go
+++ b/pkg/flows/flow_utils.go
@@ -26,8 +26,8 @@
 
 	"github.com/cevaris/ordered_map"
 	"github.com/gogo/protobuf/proto"
-	"github.com/opencord/voltha-lib-go/v3/pkg/log"
-	ofp "github.com/opencord/voltha-protos/v3/go/openflow_13"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
+	ofp "github.com/opencord/voltha-protos/v4/go/openflow_13"
 )
 
 var (