Ensure that the attribute 'acr_authentication' in Defender for IoT is not set to false

Not disabling Unauthenticated access to the ACR repository could lead to data breach.

In Azure Console -

1. Go to Azure IoT Hub.
2. Choose an IoT Hub to edit.
3. In the Defender for IoT, Choose Settings.
4. Click on the Recommendation Configuration and choose the Acr Authentication recommendation.
5. Click Enable.

In Terraform -

1. In the azurerm_iot_security_solution resource, set recommendations_enabled.acr_authentication to true.

References:
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/iot_security_solution#acr_authentication