change param name and add alias (Azure#25529)

Author: grizzlytheodore

src/Compute/Compute/ChangeLog.md

@@ -20,6 +20,7 @@
 
 -->
 ## Upcoming Release
+* Renamed parameter `-VmId` to `-SourceId` and added `-VmId` as an alias to `New-AzRestorePointCollection` cmdlet.
 
 ## Version 8.1.0
 * Added parameter `-SourceResourceId` to cmdlet `Add-AzVMDataDisk`.

src/Compute/Compute/RestorePoints/NewAzRestorePointCollection.cs

@@ -67,7 +67,8 @@ public class NewAzureRestorePointCollection : ComputeAutomationBaseCmdlet
             Mandatory = false,
             ValueFromPipeline = true,
             ParameterSetName = "RestorePointCollectionId")]
-        public string VmId { get; set; }
+        [Alias("VmId")]
+        public string SourceId { get; set; }
 
         [Parameter(
             Position = 3,
@@ -99,7 +100,7 @@ public override void ExecuteCmdlet()
                     {
                         string resourceGroup = this.ResourceGroupName;
                         string restorePointCollectionName = this.Name;
-                        string vmId = this.VmId;
+                        string vmId = this.SourceId;
                         RestorePointCollection restorePointCollection;
                         if (this.IsParameterBound(c => c.Location))
                         {

src/Compute/Compute/help/New-AzRestorePointCollection.md

@@ -14,16 +14,16 @@ Creates a New Restore Point Collection
 
 ### DefaultParameter (Default)
 ```
-New-AzRestorePointCollection [-ResourceGroupName] <String> [-Name] <String> [-VmId] <String>
+New-AzRestorePointCollection [-ResourceGroupName] <String> [-Name] <String> [-SourceId] <String>
  [-Location <String>] [-DefaultProfile <IAzureContextContainer>] [-WhatIf]
  [-Confirm] [<CommonParameters>]
 ```
 
 ### RestorePointCollectionId
 ```
-New-AzRestorePointCollection [-ResourceGroupName] <String> [-Name] <String> [[-VmId] <String>]
+New-AzRestorePointCollection [-ResourceGroupName] <String> [-Name] <String> [[-SourceId] <String>]
  [-RestorePointCollectionId] <String> -Location <String> [-DefaultProfile <IAzureContextContainer>]
- [-WhatIf] [-Confirm] [<CommonParameters>]
+  [-WhatIf] [-Confirm] [<CommonParameters>]
 ```
 
 ## DESCRIPTION
@@ -127,13 +127,13 @@ Accept pipeline input: True (ByValue)
 Accept wildcard characters: False
 ```
 
-### -VmId
-resource Id of the source resource used to create this restore point Collection
+### -SourceId
+Resource ID of the source resource used to create this restore point collection.
 
 ```yaml
 Type: System.String
 Parameter Sets: DefaultParameter
-Aliases:
+Aliases: VmId
 
 Required: True
 Position: 2
@@ -145,7 +145,7 @@ Accept wildcard characters: False
 ```yaml
 Type: System.String
 Parameter Sets: RestorePointCollectionId
-Aliases:
+Aliases: VmId
 
 Required: False
 Position: 2