Make browser auth app id optional

Headless/IntuneManagement.Headless.psm1

@@ -10,6 +10,11 @@ function Get-DefaultIntunePolicyObjectTypes
     )
 }
 
+function Get-DefaultBrowserAppId
+{
+    "14d82eec-204b-4c2f-b7e8-296a70dab67e"
+}
+
 function Get-IntuneManagementProjectRoot
 {
     Split-Path -Parent $PSScriptRoot
@@ -38,6 +43,7 @@ function Test-AuthParameters
 {
     param(
         [string]$AuthMode,
+        [string]$AppId,
         [string]$Secret,
         [string]$Certificate
     )
@@ -47,6 +53,12 @@ function Test-AuthParameters
         return
     }
 
+    if(-not $AppId)
+    {
+        throw "Specify -AppId for AppOnly auth."
+        return
+    }
+
     if((-not $Secret) -and (-not $Certificate))
     {
         throw "Specify -Secret or -Certificate for AppOnly auth, or use -AuthMode Browser."
@@ -59,7 +71,6 @@ function Invoke-IntuneHeadlessBatch
         [Parameter(Mandatory = $true)]
         [string]$TenantId,
 
-        [Parameter(Mandatory = $true)]
         [string]$AppId,
 
         [string]$Secret,
@@ -79,7 +90,12 @@ function Invoke-IntuneHeadlessBatch
         [string]$BatchFile
     )
 
-    Test-AuthParameters -AuthMode $AuthMode -Secret $Secret -Certificate $Certificate
+    if($AuthMode -eq "Browser" -and -not $AppId)
+    {
+        $AppId = Get-DefaultBrowserAppId
+    }
+
+    Test-AuthParameters -AuthMode $AuthMode -AppId $AppId -Secret $Secret -Certificate $Certificate
 
     $projectRoot = Get-IntuneManagementProjectRoot
     $runtimeModule = Join-Path $projectRoot "Runtime/IntuneManagement.Runtime.psd1"
@@ -145,7 +161,6 @@ function Export-IntunePolicies
         [Parameter(Mandatory = $true)]
         [string]$TenantId,
 
-        [Parameter(Mandatory = $true)]
         [string]$AppId,
 
         [string]$Secret,
@@ -203,7 +218,6 @@ function Import-IntunePolicies
         [Parameter(Mandatory = $true)]
         [string]$TenantId,
 
-        [Parameter(Mandatory = $true)]
         [string]$AppId,
 
         [string]$Secret,
@@ -272,7 +286,6 @@ function Invoke-IntunePolicyAction
         [Parameter(Mandatory = $true)]
         [string]$TenantId,
 
-        [Parameter(Mandatory = $true)]
         [string]$AppId,
 
         [string]$Secret,