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/adapters/iAdapter.go b/pkg/adapters/iAdapter.go
index ce0b791..b106d52 100644
--- a/pkg/adapters/iAdapter.go
+++ b/pkg/adapters/iAdapter.go
@@ -17,9 +17,9 @@
 
 import (
 	"context"
-	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
-	"github.com/opencord/voltha-protos/v3/go/openflow_13"
-	"github.com/opencord/voltha-protos/v3/go/voltha"
+	ic "github.com/opencord/voltha-protos/v4/go/inter_container"
+	"github.com/opencord/voltha-protos/v4/go/openflow_13"
+	"github.com/opencord/voltha-protos/v4/go/voltha"
 )
 
 //IAdapter represents the set of APIs a voltha adapter has to support.