Fix Databricks module default variables (#224)

* Update variables.tf

* terraform-docs: automated action

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

terraform/databricks/databricks-workspace/README.md

@@ -44,7 +44,7 @@
 | <a name="input_customer_managed_key_enabled"></a> [customer\_managed\_key\_enabled](#input\_customer\_managed\_key\_enabled) | Is the workspace enabled for customer managed key encryption? If true this enables the Managed Identity for the managed storage account. This field is only valid if the Databricks Workspace sku is set to premium. | `bool` | `false` | no |
 | <a name="input_managed_services_cmk_key_vault_key_id"></a> [managed\_services\_cmk\_key\_vault\_key\_id](#input\_managed\_services\_cmk\_key\_vault\_key\_id) | Customer managed encryption properties for the Databricks Workspace managed resources(e.g. Notebooks and Artifacts). | `string` | `null` | no |
 | <a name="input_managed_disk_cmk_key_vault_key_id"></a> [managed\_disk\_cmk\_key\_vault\_key\_id](#input\_managed\_disk\_cmk\_key\_vault\_key\_id) | Customer managed encryption properties for the Databricks Workspace managed disks. | `string` | `null` | no |
-| <a name="input_managed_disk_cmk_rotation_to_latest_version_enabled"></a> [managed\_disk\_cmk\_rotation\_to\_latest\_version\_enabled](#input\_managed\_disk\_cmk\_rotation\_to\_latest\_version\_enabled) | Whether customer managed keys for disk encryption will automatically be rotated to the latest version. | `bool` | `false` | no |
+| <a name="input_managed_disk_cmk_rotation_to_latest_version_enabled"></a> [managed\_disk\_cmk\_rotation\_to\_latest\_version\_enabled](#input\_managed\_disk\_cmk\_rotation\_to\_latest\_version\_enabled) | Whether customer managed keys for disk encryption will automatically be rotated to the latest version. | `bool` | `null` | no |
 | <a name="input_load_balancer_backend_address_pool_id"></a> [load\_balancer\_backend\_address\_pool\_id](#input\_load\_balancer\_backend\_address\_pool\_id) | Resource ID of the Outbound Load balancer Backend Address Pool for Secure Cluster Connectivity (No Public IP) workspace. Changing this forces a new resource to be created. | `string` | `null` | no |
 | <a name="input_nat_gateway_name"></a> [nat\_gateway\_name](#input\_nat\_gateway\_name) | Name of the NAT gateway for Secure Cluster Connectivity (No Public IP) workspace subnets. Changing this forces a new resource to be created. | `string` | `"nat-gateway"` | no |
 | <a name="input_public_ip_name"></a> [public\_ip\_name](#input\_public\_ip\_name) | Name of the Public IP for No Public IP workspace with managed vNet. Changing this forces a new resource to be created. | `string` | `"nat-gw-public-ip"` | no |

terraform/databricks/databricks-workspace/variables.tf

@@ -225,7 +225,7 @@ variable "managed_disk_cmk_key_vault_key_id" {
 variable "managed_disk_cmk_rotation_to_latest_version_enabled" {
   type        = bool
   description = "Whether customer managed keys for disk encryption will automatically be rotated to the latest version."
-  default     = false
+  default     = null
 }
 
 variable "load_balancer_backend_address_pool_id" {