fix: Ignore lifecycle changes, and use consistent fallback shape

[devoncrouse]

Proposed changes

Ignore lifecycle changes

• availability_domain
• defined_tags
• metadata

  # module.bastion[0].oci_core_instance.bastion must be replaced
-/+ resource "oci_core_instance" "bastion" {
      ~ availability_domain                 = "aaaa:US-ASHBURN-AD-1" -> (known after apply) # forces replacement

~ metadata                            = {
    - "ssh_authorized_keys" = <<-EOT
          ssh-rsa ...
      EOT
    - "user_data"           = "..."
  } -> (known after apply) # forces replacement

Use consistent fallback shape

• Use the same value for shape and shape_config to determine whether Flex
• Use recent shape for both

Testing

Repeated apply, manually changing tags on resources and overriding the value returned by ad.name:

terraform apply
Apply complete! Resources: 3 added, 0 changed, 0 destroyed.

terraform apply
Apply complete! Resources: 0 added, 0 changed, 0 destroyed.