[release-branch.go1.19] update codereview.cfg for release-branch.go1.19

Following go.dev/cl/334376.

Change-Id: I7e5e1b89243d1980274d27be5362acf8034998ef
Reviewed-on: https://go-review.googlesource.com/c/go/+/416176
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/codereview.cfg b/codereview.cfg
index 77a74f1..5541320 100644
--- a/codereview.cfg
+++ b/codereview.cfg
@@ -1 +1,2 @@
-branch: master
+branch: release-branch.go1.19
+parent-branch: master