Fix tflint errors

Check for latest runs and fix deprecation related errors

Example error: https://github.com/ContainerSolutions/terraform-examples/runs/7654637304?check_suite_focus=true#step:4:1494

```
Warning: Interpolation-only expressions are deprecated in Terraform v0.12.14 (terraform_deprecated_interpolation)

on main.tf line 23:
23: "${file("values.yaml")}"

Reference: https://github.com/terraform-linters/tflint/blob/v0.39.1/docs/rules/terraform_deprecated_interpolation.md
```