Update Google Cloud API client import paths

Bump version of golang.org/x/oauth2
Vendor google.golang.org/cloud/
Vendor google.golang.org/api/
Vendor cloud.google.com/go/compute/
Replace google.golang.org/cloud with cloud.google.com/go/

Fixes #30069

vendor/google.golang.org/appengine/internal/identity.go

@@ -0,0 +1,14 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package internal
+
+import netcontext "golang.org/x/net/context"
+
+// These functions are implementations of the wrapper functions
+// in ../appengine/identity.go. See that file for commentary.
+
+func AppID(c netcontext.Context) string {
+	return appID(FullyQualifiedAppID(c))
+}