Documentation incorrect for Cluster::upstream_config, and Cluster::typed_extension_protocol_options

[ravenblackx]

https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-field-config-cluster-v3-cluster-upstream-config shows 7 supported extensions, but actually only supports 4 of them.

https://www.envoyproxy.io/docs/envoy/latest/api-v3/config/cluster/v3/cluster.proto#envoy-v3-api-field-config-cluster-v3-cluster-typed-extension-protocol-options shows no supported extensions, but should be specifying at least envoy.upstreams.http.http_protocol_options, since that's apparently how we use that, at least according to the protobuf file comments:

envoy/api/envoy/extensions/upstreams/http/v3/http_protocol_options.proto

Lines 51 to 61 in d34e163

	// typed_extension_protocol_options:
	// envoy.extensions.upstreams.http.v3.HttpProtocolOptions:
	// "@type": type.googleapis.com/envoy.extensions.upstreams.http.v3.HttpProtocolOptions
	// upstream_http_protocol_options:
	// auto_sni: true
	// common_http_protocol_options:
	// idle_timeout: 1s
	// explicit_http_config:
	// http2_protocol_options:
	// max_concurrent_streams: 100
	// .... [further cluster config]

This has led to confusion in other issues.

[ravenblackx]

@yanavlasov @adisuissa as the config folks