Xray-core: Dynamic Chrome User-Agent for all HTTP requests by default (overwriteable through config) (#5658)

https://github.com/XTLS/Xray-core/issues/4996#issuecomment-3855274627
https://github.com/XTLS/Xray-core/pull/5658#issuecomment-3857332687

---------

Co-authored-by: RPRX <63339210+RPRX@users.noreply.github.com>
Co-authored-by: Fangliding <63339210+Fangliding@users.noreply.github.com>

transport/internet/websocket/config.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 
 	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/common/utils"
 	"github.com/xtls/xray-core/transport/internet"
 )
 
@@ -23,6 +24,9 @@ func (c *Config) GetRequestHeader() http.Header {
 	for k, v := range c.Header {
 		header.Add(k, v)
 	}
+	if header.Get("User-Agent") == "" {
+		header.Set("User-Agent", utils.ChromeUA)
+	}
 	return header
 }