Generation may fail for Xamarin.Android projects on Azure Devops hosted agents

When building an Xamarin.Android project on Azure Devops, setting the JavaSdkDirectory property is required, as the environment variable has no effect.

This property is not propagated to the Uno.SourceGeneration build context, making the generation fail.

Workaround

Create or update a Directory.Build.props file with this content:

<Project>
 <PropertyGroup>
   <JavaSdkDirectory Condition="'$(JavaSdkDirectory)'=='' and '$(JAVA_HOME_8_X64)'!=''">$(JAVA_HOME_8_X64)</JavaSdkDirectory>
 </PropertyGroup>
</Project>