Clicking on the app when the battery draining notification comes up will take you to the app info
You may find com.google.android.gms.policy_sidecar_aps
if you go to system -> Apps & Notifications -> See all xxx apps -> three dot menu in top right corner -> show system -> scroll down to com.google.android.gms.policy_sidecar_aps and click it -> Disable. I don't really know the function of this app but it's not system critical or you wouldn't have been able to disable it
