Remove iam_roles from net-vpc

tests/modules/net_vpc/fixture/main.tf

@@ -19,7 +19,6 @@ module "test" {
   project_id                  = var.project_id
   name                        = var.name
   iam_members                 = var.iam_members
-  iam_roles                   = var.iam_roles
   log_configs                 = var.log_configs
   log_config_defaults         = var.log_config_defaults
   peering_config              = var.peering_config

tests/modules/net_vpc/fixture/variables.tf

@@ -29,13 +29,8 @@ variable "auto_create_subnetworks" {
   default = false
 }
 
-variable "iam_roles" {
-  type    = map(list(string))
-  default = null
-}
-
 variable "iam_members" {
-  type    = map(map(list(string)))
+  type    = map(map(set(string)))
   default = null
 }