https://forums.aws.amazon.com/thread.jspa?threadID=307496
1.通过get-relational-database-parameters查询可用参数
aws lightsail get-relational-database-parameters --relational-database-name DatabaseName
2.通过update-relational-database-parameters更新参数
aws lightsail update-relational-database-parameters --relational-database-name xxxx --parameters "parameterName=time_zone,applyMethod=pending-reboot,parameterValue=Asia/Shanghai"