Updated changelog and added missing feature (#13867)

Author: dingmeng-xue

ChangeLog.md

@@ -9,6 +9,8 @@
 
 #### Az.Compute
 * New parameter 'VM' in new parameter set 'VMParameterSet' added to 'Get-AzVMDscExtensionStatus' and 'Get-AzVMDscExtension' cmdlets. 
+* Edited 'New-AzSnapshot' cmdlet to check for existing snapshot with the same name in the same resource group. 
+    - Throws an error if a duplicate snapshot exists. 
 
 #### Az.Databricks
 * Fixed an issue that may cause 'New-AzDatabricksVNetPeering' to return before it is fully provisioned (https://github.com/Azure/autorest.powershell/issues/610)

src/Compute/Compute/ChangeLog.md

@@ -23,13 +23,12 @@
 
 ## Version 4.8.0
 * New parameter `VM` in new parameter set `VMParameterSet` added to `Get-AzVMDscExtensionStatus` and `Get-AzVMDscExtension` cmdlets. 
+* Edited `New-AzSnapshot` cmdlet to check for existing snapshot with the same name in the same resource group. 
+    - Throws an error if a duplicate snapshot exists. 
 
 ## Version 4.7.0
 * Edited Get-AzVm to filter by `-Name` prior to checking for throttling due to too many resources. 
 * New cmdlet `Start-AzVmssRollingExtensionUpgrade`.
-* Edited `New-AzSnapshot` cmdlet to check for existing snapshot with the same name in the same resource group. 
-    - Throws an error if a duplicate snapshot exists. 
-
 ## Version 4.6.0
 * Added `-VmssId` parameter to `New-AzVm`
 * Added `PlatformFaultDomainCount` parameter to the `New-AzVmss` cmdlet.