generic proxy: rds support for generic proxy (#23743)

* generic proxy: rds support for generic proxy

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

* address comments

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

Signed-off-by: wbpcode <wangbaiping@corp.netease.com>

Mirrored from https://github.com/envoyproxy/envoy @ 8d523d4cc497eafb14d9400c7398a34d2dde7171

contrib/envoy/extensions/filters/network/generic_proxy/v3/generic_proxy.proto

@@ -35,7 +35,6 @@ message GenericProxy {
   oneof route_specifier {
     option (validate.required) = true;
 
-    // [#not-implemented-hide:]
     // The generic proxies route table will be dynamically loaded via the meta RDS API.
     GenericRds generic_rds = 3;
 
@@ -50,7 +49,6 @@ message GenericProxy {
   repeated config.core.v3.TypedExtensionConfig filters = 5;
 }
 
-// [#not-implemented-hide:]
 message GenericRds {
   // Configuration source specifier for RDS.
   config.core.v3.ConfigSource config_source = 1 [(validate.rules).message = {required: true}];