Readded the storage account lock

Readding the lock as it was removed to delete the role assignment. Tf Plan:

# azurerm_management_lock.system_sa_lock will be created
  + resource "azurerm_management_lock" "system_sa_lock" {
      + id         = (known after apply)
      + lock_level = "CanNotDelete"
      + name       = "osdu_system_sa_lock"
      + scope      = "/subscriptions/7c052588-ead2-45c9-9346-5b156a157bd1/resourceGroups/osdu-mvp-srdev-z98y-rg/providers/Microsoft.Storage/storageAccounts/osdumvpsrdevz98ydata"
    }