Add validation for target_types in google_bigquery_dataset_access (#15446) (#10932)

[upstream:5eb5357f26f75b3d220fea45a5a6c18a52588af6]

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

Author: modular-magician

.changelog/15446.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+bigquery: added validation for `target_types` in `google_bigquery_dataset_access`
+```

google-beta/services/bigquery/resource_bigquery_dataset_access.go

@@ -32,6 +32,7 @@ import (
 
 	"github.com/hashicorp/terraform-provider-google-beta/google-beta/tpgresource"
 	transport_tpg "github.com/hashicorp/terraform-provider-google-beta/google-beta/transport"
+	"github.com/hashicorp/terraform-provider-google-beta/google-beta/verify"
 )
 
 var bigqueryAccessRoleToPrimitiveMap = map[string]string{
@@ -258,7 +259,8 @@ This can be used e.g. in UIs which allow to enter the expression.`,
 							Description: `Which resources in the dataset this entry applies to. Currently, only views are supported,
 but additional target types may be added in the future. Possible values: VIEWS`,
 							Elem: &schema.Schema{
-								Type: schema.TypeString,
+								Type:         schema.TypeString,
+								ValidateFunc: verify.ValidateRegexp(`^[A-Z_]+$`),
 							},
 						},
 					},