Change script parameters to boolean (Azure#18708)

Co-authored-by: Chidozie Ononiwu <chononiw@microsoft.com>

Author: azure-sdk

eng/common/scripts/Update-ChangeLog.ps1

@@ -12,14 +12,11 @@ param (
   [String]$ServiceDirectory,
   [Parameter(Mandatory = $true)]
   [String]$PackageName,
-  [String]$Unreleased=$True,
-  [String]$ReplaceLatestEntryTitle = $False,
+  [Boolean]$Unreleased = $true,
+  [Boolean]$ReplaceLatestEntryTitle = $false,
   [String]$ReleaseDate
 )
 
-[Boolean]$Unreleased = [System.Convert]::ToBoolean($Unreleased)
-[Boolean]$ReplaceLatestEntryTitle = [System.Convert]::ToBoolean($ReplaceLatestEntryTitle)
-
 . (Join-Path $PSScriptRoot common.ps1)
 
 if ($ReleaseDate -and $Unreleased) {