Inclusion of Cloudhealth module has to be conditional

[the-smooth-operator]

Currently there's no way to not-include the Cloudhealth module using the code as it is.
This creates problems when one want to use this code to deploy 2 VPCs in the same account: Terraform tries creating a resource which already exists and fails.

While the workaround is clear: deleting the module inclusion, I believe we could create a better way, like the one used by DNS module and others.
But I can't think about other solution than modifying the upstream module, which can be fine.

Discussion on conditionally adding modules here: hashicorp/terraform#12906