Update Butane Config from v1.2.0 to v1.4.0

* Rename Fedora CoreOS Config (FCC) to Butane Config
* Require any snippets customizations use version v1.4.0

* https://typhoon.psdn.io/advanced/customization/#hosts

google-cloud/fedora-coreos/kubernetes/fcc/controller.yaml

@@ -1,6 +1,6 @@
 ---
 variant: fcos
-version: 1.2.0
+version: 1.4.0
 systemd:
   units:
     - name: etcd-member.service

google-cloud/fedora-coreos/kubernetes/variables.tf

@@ -71,13 +71,13 @@ variable "worker_preemptible" {
 
 variable "controller_snippets" {
   type        = list(string)
-  description = "Controller Fedora CoreOS Config snippets"
+  description = "Controller Butane snippets"
   default     = []
 }
 
 variable "worker_snippets" {
   type        = list(string)
-  description = "Worker Fedora CoreOS Config snippets"
+  description = "Worker Butane snippets"
   default     = []
 }
 

google-cloud/fedora-coreos/kubernetes/workers/fcc/worker.yaml

@@ -1,6 +1,6 @@
 ---
 variant: fcos
-version: 1.2.0
+version: 1.4.0
 systemd:
   units:
     - name: docker.service

google-cloud/fedora-coreos/kubernetes/workers/variables.tf

@@ -59,7 +59,7 @@ variable "preemptible" {
 
 variable "snippets" {
   type        = list(string)
-  description = "Fedora CoreOS Config snippets"
+  description = "Butane snippets"
   default     = []
 }