[QUESTION]:同步日志文件到Kafka，如何将原始信息写入Kafka的topic，不要添加contents,tags,time这些字段

以下为实际写入Kafka的内容，预期值为："Hello, iLogtail!"

{
	"contents": {
		"content": "Hello, iLogtail!"
	},
	"tags": {
		"host.ip": "172.17.0.1",
		"host.name": "sckf",
		"log.file.path": "/root/simple.log"
	},
	"time": 1725436015
}