fix(vertexai): set internal headers (#9151)

Follow up to #9150

vertexai/genai/client.go

@@ -25,6 +25,7 @@ import (
 
 	aiplatform "cloud.google.com/go/aiplatform/apiv1beta1"
 	pb "cloud.google.com/go/aiplatform/apiv1beta1/aiplatformpb"
+	"cloud.google.com/go/vertexai/internal"
 	"cloud.google.com/go/vertexai/internal/support"
 	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
@@ -50,6 +51,7 @@ func NewClient(ctx context.Context, projectID, location string, opts ...option.C
 	if err != nil {
 		return nil, err
 	}
+	c.SetGoogleClientInfo("gccl", internal.Version)
 	return &Client{
 		c:         c,
 		projectID: projectID,

vertexai/internal/version.go

@@ -0,0 +1,18 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+// Version is the current tagged release of the library.
+const Version = "0.4.0"