upgrade_settings is now ga, and O+C (#3252) (#1859)

* upgrade_settings is now ga, and O+C

* update tests

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/3252.txt

@@ -0,0 +1,6 @@
+```release-note:enhancement
+container: added `node_pool.upgrade_settings` (TPG only)
+```
+```release-note:enhancement
+container: updated `node_pool.upgrade_settings` to read defaults from API (TPGB only)
+```

google-beta/resource_container_node_pool.go

@@ -113,6 +113,7 @@ var schemaNodePool = map[string]*schema.Schema{
 	"upgrade_settings": {
 		Type:     schema.TypeList,
 		Optional: true,
+		Computed: true,
 		MaxItems: 1,
 		Elem: &schema.Resource{
 			Schema: map[string]*schema.Schema{