Update l0-setup to use Terraform AWS 2.0 provider

[diemonster]

l0-setup is currently broken for new installs due to incompatible params with the AWS 2.0 provider. We should either update the resource and module params to the latest standards, or force the aws provider in l0-setup to use 1.x.

[Cryowatt]

There's probably no immediate reason to update to the 2.0 provider, so I've just capped it to the latest 1.x major version.