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/adapterif/adapter_proxy_if.go b/pkg/adapters/adapterif/adapter_proxy_if.go
index de5cfc0..30fcead 100644
--- a/pkg/adapters/adapterif/adapter_proxy_if.go
+++ b/pkg/adapters/adapterif/adapter_proxy_if.go
@@ -20,7 +20,7 @@
 	"context"
 
 	"github.com/golang/protobuf/proto"
-	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
+	ic "github.com/opencord/voltha-protos/v4/go/inter_container"
 )
 
 // AdapterProxy interface for AdapterProxy implementation.
diff --git a/pkg/adapters/adapterif/core_proxy_if.go b/pkg/adapters/adapterif/core_proxy_if.go
index a7ab6dc..36939bd 100644
--- a/pkg/adapters/adapterif/core_proxy_if.go
+++ b/pkg/adapters/adapterif/core_proxy_if.go
@@ -19,7 +19,7 @@
 import (
 	"context"
 
-	"github.com/opencord/voltha-protos/v3/go/voltha"
+	"github.com/opencord/voltha-protos/v4/go/voltha"
 )
 
 // CoreProxy interface for voltha-go coreproxy.
diff --git a/pkg/adapters/adapterif/events_proxy_if.go b/pkg/adapters/adapterif/events_proxy_if.go
index dbd8140..7d8a053 100644
--- a/pkg/adapters/adapterif/events_proxy_if.go
+++ b/pkg/adapters/adapterif/events_proxy_if.go
@@ -18,7 +18,7 @@
 
 import (
 	"context"
-	"github.com/opencord/voltha-protos/v3/go/voltha"
+	"github.com/opencord/voltha-protos/v4/go/voltha"
 )
 
 // EventProxy interface for eventproxy