Fix UserIdentity issue for VMSS

Author: hyonholee

src/ResourceManager/Compute/Commands.Compute.Test/ScenarioTests/VirtualMachineScaleSetTests.ps1

@@ -1011,6 +1011,7 @@ function Test-VirtualMachineScaleSetIdentity
         Assert-AreEqual "SystemAssigned" $result.Identity.Type;
         Assert-NotNull $result.Identity.PrincipalId;
         Assert-NotNull $result.Identity.TenantId;
+        Assert-Null $result.Identity.UserAssignedIdentities;
 
         # Validate Network Profile
         Assert-AreEqual 'test' $result.VirtualMachineProfile.NetworkProfile.NetworkInterfaceConfigurations[0].Name;
@@ -1046,6 +1047,7 @@ function Test-VirtualMachineScaleSetIdentity
         Assert-AreEqual "SystemAssigned" $vmssResult.Identity.Type;
         Assert-NotNull $vmssResult.Identity.PrincipalId;
         Assert-NotNull $vmssResult.Identity.TenantId;
+        Assert-Null $result.Identity.UserAssignedIdentities;
 
         $vmssInstanceViewResult = Get-AzureRmVmss -ResourceGroupName $rgname -VMScaleSetName $vmssName -InstanceView;
         Assert-AreEqual "ProvisioningState/succeeded" $vmssInstanceViewResult.VirtualMachine.StatusesSummary[0].Code;

src/ResourceManager/Compute/Commands.Compute/Generated/Models/ComputeAutoMapperProfile.cs

@@ -137,8 +137,10 @@ private static void Initialize()
                 cfg.CreateMap<TO.PSRunCommandDocumentBase, FROM.RunCommandDocumentBase>();
                 cfg.CreateMap<FROM.RollingUpgradeStatusInfo, TO.PSRollingUpgradeStatusInfo>();
                 cfg.CreateMap<TO.PSRollingUpgradeStatusInfo, FROM.RollingUpgradeStatusInfo>();
-                cfg.CreateMap<FROM.VirtualMachineScaleSetIdentity, TO.PSVirtualMachineScaleSetIdentity>();
-                cfg.CreateMap<TO.PSVirtualMachineScaleSetIdentity, FROM.VirtualMachineScaleSetIdentity>();
+                cfg.CreateMap<FROM.VirtualMachineScaleSetIdentity, TO.PSVirtualMachineScaleSetIdentity>()
+                    .ForMember(c => c.UserAssignedIdentities, o => o.Condition(r => (r.UserAssignedIdentities != null)));
+                cfg.CreateMap<TO.PSVirtualMachineScaleSetIdentity, FROM.VirtualMachineScaleSetIdentity>()
+                    .ForMember(c => c.UserAssignedIdentities, o => o.Condition(r => (r.UserAssignedIdentities != null)));
                 cfg.CreateMap<FROM.VirtualMachineScaleSet, TO.PSVirtualMachineScaleSet>()
                     .ForMember(c => c.Zones, o => o.Condition(r => (r.Zones != null)));
                 cfg.CreateMap<TO.PSVirtualMachineScaleSet, FROM.VirtualMachineScaleSet>()