admin sdkのfirestore <img width="789" alt="2018-12-02 18 06 57" src="https://user-images.githubusercontent.com/22343391/49337961-5436be80-f65f-11e8-98f9-3c829c346ec8.png"> firebase sdkのfirestore <img width="799" alt="2018-12-02 18 06 31" src="https://user-images.githubusercontent.com/22343391/49337994-b7c0ec00-f65f-11e8-9e47-6fb2ea954861.png"> firebaseのfirestoreとadmin sdkのfirestoreは型が違うっぽいです。
