New build failure in SiteCore component sample against MSBuild 14

I'm seeing a new issue in c6 builds when using the VS 2015 build tools. The SiteCore component fails to build due to:

> error CS1703: Multiple assemblies with equivalent identity have been imported

This project builds successfully in VS2015 and from command line with MSBuild 14 using cycle 5 builds, but fails with cycle 6 builds. This project builds successfully on Mac against cycle 6 builds, as well as in XS on windows against cycle 6 builds (which does not yet support 2015 build tools).

Steps to reproduce from Command line:
1. Download the SiteCore component

> https://components.xamarin.com/view/Sitecore.Mobile.SDK

2. Download xamarin-component.exe

> https://components.xamarin.com/submit/xpkg

3. xamarin-component.exe restore samples\AndroidMobileSdkDemo\AndroidMobileSdkDemo.sln
4. msbuild /t:SignAndroidPackage samples\AndroidMobileSdkDemo\AndroidMobileSdkDemo\AndroidMobileSdkDemo.csproj

Successful C5 build output:
https://gist.github.com/pjcollins/b59369d82f89ba289b86

Failed C6 build output:
https://gist.github.com/pjcollins/d596f7a09a46f9358105

##### Environment #####
Operating System: Windows 10
Repo Name: XamarinVS.git
Branch Name: cycle6
Build Revision: 8150bab699a83061f39a1cd5e35303e793972caa
MonoDroidHash: cycle6 2eefd39c431d80d2d004877f8ef84760b95d8e20


Reference: https://bugzilla.xamarin.com/show_bug.cgi?id=35582