Update to "Example 1" of "New-AzRouteServer" (#19091)

* Update Example 1

The example had cmdlets with null variables for their parameters which caused those cmdlets to fail. I replaced those variables with string values.

* Update New-AzRouteServer.md

Co-authored-by: Yeming Liu <[email protected]>
Co-authored-by: Yunchi Wang <[email protected]>
Co-authored-by: wyunchi-ms <[email protected]>

Author: 3 people

src/Network/Network/help/New-AzRouteServer.md

@@ -23,14 +23,16 @@ The **New-AzRouteServer** cmdlet creates an Azure RouteServer
 
 ## EXAMPLES
 
-### Example 1
+### Example 1: Create a new router server
 ```powershell
-$subnet = New-AzVirtualNetworkSubnetConfig -Name $subnetName -AddressPrefix 10.0.0.0/24
-$vnet = New-AzVirtualNetwork -Name $vnetName -ResourceGroupName $resourceGroupName -Location $resourceGroupLocation -AddressPrefix 10.0.0.0/16 -Subnet $subnet
-$subnetId = (Get-AzVirtualNetworkSubnetConfig -Name $subnetName -VirtualNetwork $vnet).Id
-$publicIpAddress = New-AzPublicIpAddress -Name $publicIpAddressName -ResourceGroupName $rgName -AllocationMethod Static -Location $rglocation -Sku Standard -Tier Regional
+New-AzResourceGroup -Name myResourceGroup -Location eastus
 
-New-AzRouteServer -RouteServerName $routeServerName -ResourceGroupName $resourceGroupName -Location $resourceGroupLocation -HostedSubnet $subnetId -PublicIpAddress $publicIpAddress -HubRoutingPreference "AsPath"
+$subnet = New-AzVirtualNetworkSubnetConfig -Name RouteServerSubnet -AddressPrefix 10.0.0.0/24
+$vnet = New-AzVirtualNetwork -Name myVNet -ResourceGroupName myResourceGroup -Location eastus -AddressPrefix 10.0.0.0/16 -Subnet $subnet
+$subnetId = (Get-AzVirtualNetworkSubnetConfig -Name RouteServerSubnet -VirtualNetwork $vnet).Id
+$publicIpAddress = New-AzPublicIpAddress -Name myRouteServerIP -ResourceGroupName myResourceGroup -AllocationMethod Static -Location eastus -Sku Standard -Tier Regional
+
+New-AzRouteServer -RouteServerName myRouteServer -ResourceGroupName myResourceGroup -Location eastus -HostedSubnet $subnetId -PublicIpAddress $publicIpAddress
 ```
 
 ## PARAMETERS