TBR: Changes to accompany https://vanadium-review.googlesource.com/10622

MultiPart: 2/3
Change-Id: Id53be90a231ef7ee5193d88a927b018c37e088b7
diff --git a/go/src/v.io/x/playground/builder/services.go b/go/src/v.io/x/playground/builder/services.go
index e332178..187656d 100644
--- a/go/src/v.io/x/playground/builder/services.go
+++ b/go/src/v.io/x/playground/builder/services.go
@@ -56,6 +56,7 @@
 		"proxyd",
 		"-log_dir=/tmp/logs",
 		"-name="+proxyName,
+		"-access-list", fmt.Sprintf("{\"In\":[\"%v\"]}", identityProvider),
 		"-v23.tcp.address=127.0.0.1:0")
 	if _, err := startAndWaitFor(cmd, timeLimit, regexp.MustCompile("NAME=(.*)")); err != nil {
 		return nil, fmt.Errorf("Error starting proxy: %v", err)