Extend support for tag bindings to more modules (#2307)

* fix kms tag bindings

* bigquery dataset

* fix bigquery

* cloud run

* normalize variable type

* rename gcs heading

* kms example test

* fix bigquery

* fix cloud run

* cloud run v2

modules/gcs/README.md

@@ -8,7 +8,7 @@
 - [GCS notifications](#gcs-notifications)
 - [Object upload](#object-upload)
 - [IAM](#iam)
-- [Tags](#tags)
+- [Tag Bindings](#tag-bindings)
 - [Variables](#variables)
 - [Outputs](#outputs)
 <!-- END TOC -->
@@ -247,7 +247,7 @@ module "bucket" {
 # tftest modules=1 resources=2 inventory=iam-bindings-additive.yaml e2e
 ```
 
-## Tags
+## Tag Bindings
 
 Refer to the [Creating and managing tags](https://cloud.google.com/resource-manager/docs/tags/tags-creating-and-managing) documentation for details on usage.
 
@@ -307,10 +307,10 @@ module "bucket" {
 | [retention_policy](variables.tf#L236) | Bucket retention policy. | <code title="object&#40;&#123;&#10;  retention_period &#61; number&#10;  is_locked        &#61; optional&#40;bool&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
 | [soft_delete_retention](variables.tf#L245) | The duration in seconds that soft-deleted objects in the bucket will be retained and cannot be permanently deleted. Set to 0 to override the default and disable. | <code>number</code> |  | <code>null</code> |
 | [storage_class](variables.tf#L251) | Bucket storage class. | <code>string</code> |  | <code>&#34;MULTI_REGIONAL&#34;</code> |
-| [tag_bindings](variables.tf#L261) | Tag bindings for this folder, in key => tag value id format. | <code>map&#40;string&#41;</code> |  | <code>null</code> |
-| [uniform_bucket_level_access](variables.tf#L267) | Allow using object ACLs (false) or not (true, this is the recommended behavior) , defaults to true (which is the recommended practice, but not the behavior of storage API). | <code>bool</code> |  | <code>true</code> |
-| [versioning](variables.tf#L273) | Enable versioning, defaults to false. | <code>bool</code> |  | <code>false</code> |
-| [website](variables.tf#L279) | Bucket website. | <code title="object&#40;&#123;&#10;  main_page_suffix &#61; optional&#40;string&#41;&#10;  not_found_page   &#61; optional&#40;string&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
+| [tag_bindings](variables.tf#L261) | Tag bindings for this folder, in key => tag value id format. | <code>map&#40;string&#41;</code> |  | <code>&#123;&#125;</code> |
+| [uniform_bucket_level_access](variables.tf#L268) | Allow using object ACLs (false) or not (true, this is the recommended behavior) , defaults to true (which is the recommended practice, but not the behavior of storage API). | <code>bool</code> |  | <code>true</code> |
+| [versioning](variables.tf#L274) | Enable versioning, defaults to false. | <code>bool</code> |  | <code>false</code> |
+| [website](variables.tf#L280) | Bucket website. | <code title="object&#40;&#123;&#10;  main_page_suffix &#61; optional&#40;string&#41;&#10;  not_found_page   &#61; optional&#40;string&#41;&#10;&#125;&#41;">object&#40;&#123;&#8230;&#125;&#41;</code> |  | <code>null</code> |
 
 ## Outputs
 

modules/gcs/tags.tf

@@ -15,7 +15,7 @@
  */
 
 resource "google_tags_location_tag_binding" "binding" {
-  for_each  = coalesce(var.tag_bindings, {})
+  for_each  = var.tag_bindings
   parent    = "//storage.googleapis.com/projects/_/buckets/${local.prefix}${lower(var.name)}"
   tag_value = each.value
   location  = var.location

modules/gcs/variables.tf

@@ -261,7 +261,8 @@ variable "storage_class" {
 variable "tag_bindings" {
   description = "Tag bindings for this folder, in key => tag value id format."
   type        = map(string)
-  default     = null
+  nullable    = false
+  default     = {}
 }
 
 variable "uniform_bucket_level_access" {