housekeeping: Add a empty Pack to Droid

src/Camelotia.Presentation.Xamarin.Android/Camelotia.Presentation.Xamarin.Droid.csproj

@@ -134,5 +134,6 @@
       <SubType>Designer</SubType>
     </AndroidResource>
   </ItemGroup>
+  <Target Name="Pack"></Target>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
-</Project>
+</Project>