Expect error when clearing custom performance in Filestore (#13756) (#22486)

[upstream:135ce53aab48839b20eb9f4c270b994834406664]

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

Author: modular-magician

google/services/filestore/resource_filestore_instance_test.go

@@ -6,6 +6,7 @@ import (
 	"context"
 	"fmt"
 	"reflect"
+	"regexp"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
@@ -325,13 +326,8 @@ func TestAccFilestoreInstance_performanceConfig(t *testing.T) {
 				ImportStateVerifyIgnore: []string{"zone"},
 			},
 			{
-				Config: testAccFilestoreInstance_defaultConfig(name, location, tier),
-			},
-			{
-				ResourceName:            "google_filestore_instance.instance",
-				ImportState:             true,
-				ImportStateVerify:       true,
-				ImportStateVerifyIgnore: []string{"zone"},
+				Config:      testAccFilestoreInstance_defaultConfig(name, location, tier),
+				ExpectError: regexp.MustCompile("custom performance cannot be cleared"),
 			},
 		},
 	})