Fix build.ps1, failing in security tools (#384)

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#### Summary <!-- Provide a general summary of your changes -->
Fix build.ps1, failing in security tools

#### Work Item(s) <!-- Add the issue number here after the #. The issue
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Fixes AB#492601, Fixes AB#492573

build.ps1

@@ -11,6 +11,7 @@
         .\build.ps1 -ALGoProject "System Application"
         .\build.ps1 -ALGoProject "Test Stability Tools" -AutoFill
 #>
+[Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSAvoidUsingConvertToSecureStringWithPlainText', '', Justification = 'local build')]
 param
 (
     [Parameter(Mandatory=$true)]
@@ -28,9 +29,8 @@ if (-not (Get-Module -ListAvailable -Name "BCContainerHelper")) {
 if ($AutoFill) {
     Add-Type -AssemblyName System.Web
 
-    $password = [System.Web.Security.Membership]::GeneratePassword(20, 5)
-    [Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSAvoidUsingConvertToSecureStringWithPlainText', Justification = 'local build')]
-    $credential = New-Object -TypeName pscredential -ArgumentList admin, ConvertTo-SecureString -String $password -AsPlainText -Force
+    [securestring] $securePassword = ConvertTo-SecureString -String $([System.Web.Security.Membership]::GeneratePassword(20, 5)) -AsPlainText -Force
+    $credential = New-Object -TypeName pscredential -ArgumentList admin, $securePassword
     $licenseFileUrl = 'none'
     $containerName = "bcserver"
     $auth = "UserPassword"