TestAccAWSEC2VPC_CidrBlock: Add default attribute values.

Author: ewbankkit

internal/aws/ec2/vpc_resource_test.go

@@ -36,7 +36,10 @@ func TestAccAWSEC2VPC_CidrBlock(t *testing.T) {
 func testAccAWSEC2VPCCidrBlockConfig(td *acctest.TestData, rName, cidrBlock string) string {
 	return fmt.Sprintf(`
 resource %[1]q %[2]q {
-  cidr_block = %[4]q
+  cidr_block           = %[4]q
+  enable_dns_hostnames = false
+  enable_dns_support   = true
+  instance_tenancy     = "default"
 
   tags = [
     {