PowerShell to configure idle timeout for an endpoint

The idle timeout for a public Azure endpoint can only be configured at the time of creating the endpoint:

Get-AzureVM -ServiceName "<CloudServiceName>
                        -Name "<VMName>" |
Add-AzureEndpoint -Name "<EndpointName>"
                                  -Protocol "tcp"
                                  -PublicPort <PublicPort>
                                  -LocalPort <PrivatePort>
                                  -IdleTimeInMinutes <NumMinutes> |
Update-AzureVM