Add warnings for Basic SKU when create Public IP and LB (Azure#19183)

* added warning about sku switching to standard

* Apply suggestions from code review

Co-authored-by: Yeming Liu <11371776+isra-fel@users.noreply.github.com>

Author: bhavanabheem

src/Network/Network/ChangeLog.md

@@ -20,6 +20,9 @@
 
 ## Upcoming Release
 * Fixed a bug that removes existing resource tags during a Set-AzFirewallPolicy command 
+* Added breaking change attribute to notify that public ip address sku default behaviour will be changed
+    - `New-AzPublicIpAddress`
+    - `New-AzLoadBalancer`
 
 ## Version 4.19.0
 * Updated cmdlets to add new property of `ExplicitProxy` in Azure Firewall Policy.

src/Network/Network/LoadBalancer/NewAzureRMLoadBalancerCommand.cs

@@ -25,9 +25,11 @@
 using System.Management.Automation;
 using AutoMapper;
 using MNM = Microsoft.Azure.Management.Network.Models;
+using Microsoft.WindowsAzure.Commands.Common.CustomAttributes;
 
 namespace Microsoft.Azure.Commands.Network
 {
+    [GenericBreakingChange("It is recommended to use parameter '-Sku Standard' to create new IP address. Please note that it will become the default behavior for IP address creation in the future.")]
     [Cmdlet(VerbsCommon.New, ResourceManager.Common.AzureRMConstants.AzureRMPrefix + "LoadBalancer", SupportsShouldProcess = true), OutputType(typeof(PSLoadBalancer))]
     public partial class NewAzureRmLoadBalancer : NetworkBaseCmdlet
     {

src/Network/Network/PublicIpAddress/NewAzurePublicIpAddressCommand.cs

@@ -30,6 +30,7 @@ namespace Microsoft.Azure.Commands.Network
 {
     [GenericBreakingChange("Default behaviour of Zone will be changed", OldWay = "Sku = Standard means the Standard Public IP is zone-redundant.",
         NewWay = "Sku = Standard and Zone = {} means the Standard Public IP has no zones. If you want to create a zone-redundant Public IP address, please specify all the zones in the region. For example, Zone = ['1', '2', '3'].")]
+    [GenericBreakingChange("It is recommended to use parameter '-Sku Standard' to create new IP address. Please note that it will become the default behavior for IP address creation in the future.")]
     [Cmdlet("New", ResourceManager.Common.AzureRMConstants.AzureRMPrefix + "PublicIpAddress", SupportsShouldProcess = true),OutputType(typeof(PSPublicIpAddress))]
     public class NewAzurePublicIpAddressCommand : PublicIpAddressBaseCmdlet
     {