Implement restrictions at https://tools.ietf.org/html/draft-ietf-quic-transport-27#section-7.3.1. This prepares for 0-rtt on the client side. This change should be no-op for current deployment in gfe because config is currently only set once. gfe-relnote: unused code. not protected. PiperOrigin-RevId: 308861599 Change-Id: I0c8182f3d11330f40024dca76de9fed6d383f8d1