Shanghai to Bali with layover in Seoul

We are traveling from Seoul to Shanghai on 30 March 2017 then leave on 1 April 2017 to Bali. We have a 4 hour layover in Seoul.
Can we still take advantage of 144 hour free visa.

On 1 April 2017 our travel plans:
Shanghai to Seoul
4 hour Layover in Seoul
Seoul to Bali (Indonesia)

We leave Bali on 7 April 2017 back to Seoul.
Please advise.
Thank you.