interpolation syntax in cloud-dns

when we ran the _terraform init,_ it is Warning with **Interpolation-only expressions are deprecated** .

reference path:-
[dns_zones](https://github.com/GoogleCloudPlatform/solution-acceleration-toolkit/blob/master/templates/tfengine/components/resources/dns_zones/main.tf)
[gke_clusters](https://github.com/GoogleCloudPlatform/solution-acceleration-toolkit/blob/master/templates/tfengine/components/resources/gke_clusters/main.tf)

### Observed behavior

Warning: Interpolation-only expressions are deprecated

on main.tf line 165, in module "example_dev":
165: records = ["${google_compute_global_address.ingress_static_ip.address}"]

Terraform 0.11 and earlier required all non-constant expressions to be
provided via interpolation syntax, but this pattern is now deprecated. To
silence this warning, remove the "${ sequence from the start and the }"
sequence from the end of this expression, leaving just the inner expression.

### Terraform Configuration

```hcl
module "example_qa" {
source = "terraform-google-modules/cloud-dns/google"
version = "~> 3.0.0"

name = "example-qa"
project_id = module.project.project_id
domain = "example-qa.example.com."
type = "public"

recordsets = [
{
name = "XXXXXXX"
records = ["${google_compute_global_address.ingress_static_ip.address}"]
ttl = 30
type = "A"
},
{
name = "XXXXXXX"
records = ["${google_compute_global_address.ingress_static_ip.address}"]
ttl = 30
type = "A"
},
]

}
```

### Terraform Version

```sh
Terraform v0.14.0
```

### Additional information

#182