pub fn http2_max_header_list_size(self, size: u32) -> Self {
        Endpoint {
            http2_max_header_list_size: Some(size),
            ..self
        }
    }
Sets the max size of received header frames.

This will default to whatever the default in hyper is. As of v1.4.1, it is 16 KiB.
tonic/src/transport/channel/endpoint.rs