Deprecated bool_to_object custom expander (GoogleCloudPlatform#13917)

Co-authored-by: Cameron Thornton <camthornton@google.com>

Author: hao-nan-li

mmv1/products/billingbudget/Budget.yaml

@@ -412,7 +412,8 @@ properties:
           - 'amount.0.specified_amount'
           - 'amount.0.last_period_amount'
         custom_flatten: 'templates/terraform/custom_flatten/object_to_bool.go.tmpl'
-        custom_expand: 'templates/terraform/custom_expand/bool_to_object.go.tmpl'
+        # THIS TEMPLATE IS DEPRECATED, DO NOT USE FOR NEW FIELDS
+        custom_expand: 'templates/terraform/custom_expand/deprecated_bool_to_object.go.tmpl'
   - name: 'thresholdRules'
     type: Array
     description: |

mmv1/products/dlp/DeidentifyTemplate.yaml

@@ -349,7 +349,8 @@ properties:
                       description: |
                         Replace each matching finding with the name of the info type.
                       custom_flatten: 'templates/terraform/custom_flatten/object_to_bool.go.tmpl'
-                      custom_expand: 'templates/terraform/custom_expand/bool_to_object.go.tmpl'
+                      # THIS TEMPLATE IS DEPRECATED, DO NOT USE FOR NEW FIELDS
+                      custom_expand: 'templates/terraform/custom_expand/deprecated_bool_to_object.go.tmpl'
                     - name: 'characterMaskConfig'
                       type: NestedObject
                       description: |

mmv1/products/dns/ManagedZone.yaml

@@ -403,7 +403,8 @@ properties:
     min_version: 'beta'
     immutable: true
     custom_flatten: 'templates/terraform/custom_flatten/object_to_bool.go.tmpl'
-    custom_expand: 'templates/terraform/custom_expand/bool_to_object.go.tmpl'
+    # THIS TEMPLATE IS DEPRECATED, DO NOT USE FOR NEW FIELDS
+    custom_expand: 'templates/terraform/custom_expand/deprecated_bool_to_object.go.tmpl'
   - name: 'serviceDirectoryConfig'
     type: NestedObject
     description:

…orm/custom_expand/bool_to_object.go.tmpl …expand/deprecated_bool_to_object.go.tmplmmv1/templates/terraform/custom_expand/bool_to_object.go.tmpl renamed to mmv1/templates/terraform/custom_expand/deprecated_bool_to_object.go.tmpl mmv1/templates/terraform/custom_expand/bool_to_object.go.tmpl renamed to mmv1/templates/terraform/custom_expand/deprecated_bool_to_object.go.tmpl

@@ -10,6 +10,9 @@
 	See the License for the specific language governing permissions and
 	limitations under the License.
 */ -}}
+
+{{/* THIS TEMPLATE IS DEPRECATED, DO NOT USE FOR NEW FIELDS */}}
+
 func expand{{$.GetPrefix}}{{$.TitlelizeProperty}}(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
 	if v == nil || !v.(bool) {
         return nil, nil