swagger: Fix swagger definition for machine-config
swagger: Fix swagger definition for machine-config

Mark the mandatory fields in machine-config as required.
This will ensure that swagger code generators will not omit
boolean fields when set to false.

Signed-off-by: Manohar Castelino <f32964ad29a31ea3feb8b48f3bb1748edf23aee2@intel.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker