[Windows build perf] UnpackLibraryResources should consume .NET assemblies from the Mac installation

[emaf]

When building an iOS project remotely from Windows, the UnpackLibraryResources taks is comparing/copying ~ 150 .NET assemblies over to the Mac that already exist in the SDK installation. The task seems to have enough information to avoid copying those and take them from the installation directory on the Mac.

This also impacts incremental builds because even though we cache files on the Mac, comparing 150 files takes a considerable amount of time.

Expected Behavior

Files that are part of the SDK installed on the Mac should be consumed from there

Actual Behavior

We are copying unnecesary files over the network

Build Logs

Note: this logs were taken when building from a Dev Box
Binlogs.zip

[rolfbjarne]

We might be able to execute this task fully on Windows, as far as I can tell there's nothing that needs to happen on a Mac.