Support for system assigned identity in automation accounts

[hriaz]

When trying to use managed identity in the automation account, it does not get recognized at all. This feature is currently in preview however there is a need to support this for the future. Preview details are here

identity = {
      type = "SystemAssigned"
    }

[arnaudlh]

hi @hriaz I dont see it implemented in the azurerm provider yet, so we will have to wait before it can be included. https://github.com/terraform-providers/terraform-provider-azurerm here is the issue: https://github.com/terraform-providers/terraform-provider-azurerm/issues/11503

[jleonelion]

@LaurentLesle please assign to me and let me know branch I should submit PR to

[LaurentLesle]

Added with Merged Add support for MSI and private endpoints to automation account #1286