use min_len instead of min_bytes for golang.proto. (#25206)

Signed-off-by: wangfakang <fakangwang@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ a8a39af371cceaca4c08ce8637d5980fe14de151

contrib/envoy/extensions/filters/http/golang/v3alpha/golang.proto

@@ -51,7 +51,7 @@ message Config {
   // and can be used to associate :ref:`route and virtualHost plugin configuration
   // <envoy_v3_api_field_extensions.filters.http.golang.v3alpha.ConfigsPerRoute.plugins_config>`.
   //
-  string plugin_name = 3 [(validate.rules).string = {min_bytes: 1}];
+  string plugin_name = 3 [(validate.rules).string = {min_len: 1}];
 
   // Configuration for the Go plugin.
   //