Clean up code on SETTINGS. SETTINGS are now only sent in HTTP/3. And since it's sent once encryption is established, it doesn't need to be explicitly sent before PRIORITY is written. gfe-relnote: protected by disabled v99 flag. PiperOrigin-RevId: 276159509 Change-Id: I8a090fcc54c222578ffcb0bf9c66dc00c0f2e20f