[Import GeoJSON] Update import function to always include auditInfo

This should be added to `created` and `lastModified` fields in:

- [ ] Surveys
- [ ] LOIs
- [ ] Submissions

No changes are needed to the current structure of auditInfo:

```
class AuditInfo {
user: User,
clientTime: Date,
serverTime: Date | FieldValue
}
```

On updates, `serverTime` should always be set to `serverTimestamp()` `FieldValue`.