应用: 抖音
任务: 打开抖音，进入消息页面，给朋友回复私信‘你好，世界’
操作步骤:
step_id: 0
action: CLICK
step_id: 1
action: CLICK
step_id: 2
action: CLICK
step_id: 3
action: CLICK
step_id: 4
action: TYPE
type_text: 你好，世界
step_id: 5
action: CLICK
step_id: 6
action: STOP