Request body
In the request body, supply a Files resource with the following properties as the metadata. For more information, see the document on media upload.
..............
parents[] list The IDs of the parent folders which contain the file.
If not specified as part of a create request, the file will be placed directly in the user's My Drive folder. If not specified as part of a copy request, the file will inherit any discoverable parents of the source file. Update requests must use the addParents and removeParents parameters to modify the parents list
твой вариант подойдет если надо не null выдавать в качестве дефолта, а так это то же самое