Consolidate gogo/protobuf dependencies under our own protobuf package

This would make gogo/protobuf migration easier.

Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>

services/introspection/introspection.go

@@ -22,7 +22,7 @@ import (
 	api "github.com/containerd/containerd/api/services/introspection/v1"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/log"
-	ptypes "github.com/gogo/protobuf/types"
+	ptypes "github.com/containerd/containerd/protobuf/types"
 )
 
 // Service defines the instrospection service interface

services/introspection/local.go

@@ -27,9 +27,9 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/filters"
 	"github.com/containerd/containerd/plugin"
+	ptypes "github.com/containerd/containerd/protobuf/types"
 	"github.com/containerd/containerd/services"
 	"github.com/gogo/googleapis/google/rpc"
-	ptypes "github.com/gogo/protobuf/types"
 	"github.com/google/uuid"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/status"

services/introspection/service.go

@@ -22,8 +22,8 @@ import (
 
 	api "github.com/containerd/containerd/api/services/introspection/v1"
 	"github.com/containerd/containerd/plugin"
+	ptypes "github.com/containerd/containerd/protobuf/types"
 	"github.com/containerd/containerd/services"
-	ptypes "github.com/gogo/protobuf/types"
 	"google.golang.org/grpc"
 )