应用: 快手
任务: 在快手上，把系统字体大小设置成‘中等’
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: CLICK
step_id: 5
action: CLICK