Comment 4 for bug 1871409

I think we can enable config_drive to True/False, only a boolean type, that in:

* Create Server ``POST /servers`` API, request config_drive is boolean type [1], it's parameter type is boolean
* List Servers Detailed ``GET /servers/detail`` API, return "config_drive": "" [2], it's parameter type is string
* Show Server Details ``GET /servers/{server_id}`` API, return "config_drive": "" [2], it's parameter type is string

We have already done boolean verification when the request was created, IMO the response can be consistent.
This way we need to change the nova api, that need to add a micorversion to support, => https://etherpad.openstack.org/p/nova-api-cleanup L86.

[1]https://opendev.org/openstack/nova/src/branch/master/api-ref/source/parameters.yaml#L2079-L2089
[2]https://opendev.org/openstack/nova/src/branch/master/api-ref/source/parameters.yaml#L2097-L2104