Example doc to import (json file with this attached):
```
[{
  "doubleNum":

}]
```

Results in Int32 type:

Probably needs a `promoteValues: false` in the ejson deserialize: https://github.com/mongodb-js/compass/blob/50b2b2966e1eae0c92a60877f40a5e94624cec14/packages/compass-import-export/src/import/import-json.ts#L81 
Let's also add a regression test.