r/aws_route53_health_check: Validate reference_name (#12873)

Support plan-time validation for the length of the reference_name
argument. Since this resource auto-appends a unique string to the
provided argument, this is necessary to avoid obtuse errors on apply.
This validates the provided reference_name plus the generated string is
no longer than 64 chars, the actual API limit.

Since the generated unique ID is 37 chars, the `reference_name` argument
cannot exceed 27 characters.

Closes #7248

Co-Authored-By: Brian Flad <bflad417@gmail.com>

Co-authored-by: Brian Flad <bflad417@gmail.com>

aws/resource_aws_route53_health_check.go

@@ -128,6 +128,12 @@ func resourceAwsRoute53HealthCheck() *schema.Resource {
  Type: schema.TypeString,
  Optional: true,
  ForceNew: true,
+ // The max length of the reference name is 64 characters for the API.
+ // Terraform appends a 37-character unique ID to the provided
+ // reference_name. This limits the length of the resource argument to 27.
+ //
+ // Example generated suffix: -terraform-20190122200019880700000001
+ ValidateFunc: validation.StringLenBetween(0, (64 - resource.UniqueIDSuffixLength - 11)),
  },
  "enable_sni": {
  Type: schema.TypeBool,