Vietnam to Jeju Island via Shanghai for a Indian passport holder

Hi,
I have a 9 hour layover in Shanghai on my way to Jeju island from Vietnam. I am a Indian passport holder and doesn't need a visa for Jeju. From the above posts I understand that for less than 24 hours I don't need a transit entry permit. But am I allowed to go out of the Airport in that case? Any guidance would be appreciated.
Thanks!