Update src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.CrossGen.targets

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: kotlarmilos

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.CrossGen.targets

@@ -24,7 +24,7 @@ Copyright (c) .NET Foundation. All rights reserved.
     <PublishReadyToRunComposite Condition="'$(PublishReadyToRunUseCrossgen2)' != 'true' or '$(SelfContained)' != 'true'">false</PublishReadyToRunComposite>
     <PublishReadyToRunUseRuntimePackOptimizationData Condition="'$(PublishReadyToRunUseRuntimePackOptimizationData)' == ''">true</PublishReadyToRunUseRuntimePackOptimizationData>
     <PublishReadyToRunPerfmapFormatVersion Condition="'$(PublishReadyToRunPerfmapFormatVersion)' == ''">1</PublishReadyToRunPerfmapFormatVersion>
-    <PublishReadyToRunEmitSymbols Condition="'$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'tvos' or '$(TargetPlatformIdentifier)' == 'maccatalyst'">false</PublishReadyToRunEmitSymbols>
+    <PublishReadyToRunEmitSymbols Condition="'$(PublishReadyToRunEmitSymbols)' == '' and ('$(TargetPlatformIdentifier)' == 'ios' or '$(TargetPlatformIdentifier)' == 'tvos' or '$(TargetPlatformIdentifier)' == 'maccatalyst')">false</PublishReadyToRunEmitSymbols>
   </PropertyGroup>
 
   <!--