What is EastworldService running from the Play Store app?
The "Eastworld Service" is an integral part of the Google Mobile Services (GMS). 

From it's code it seems for example to collects some device statistical data like app (un)installations, available Playstore updates, screen on-times, charging times...

BTW: The GMS core package also contains a "Westworld" service and other funny names. Also the Thunderbird service is mentioned here, seems to be related to Google Cloud Messaging (better known as Push Messaging system or "Firebase Messaging").