[tests] fix msbuild tests (#4450)

* [tests] fix msbuild tests

those tests are failing sice the move to SDK-style project for
Xaml.UnitTests

* [Build] Copy xaml.unittests artifacts

* [build] Xaml.UnitTests lives in the debug/net47 foder

Xamarin.Forms.Xaml.UnitTests/MSBuild/MSBuildTests.cs

@@ -67,7 +67,7 @@ namespace Xamarin.Forms.Xaml.UnitTests
 			Directory.CreateDirectory (tempDirectory);
 
 			//We need to copy Xamarin.Forms.targets to the test directory, to reliably import them
-			var xamarinFormsTargets = Path.Combine (testDirectory, "..", "..", "..", ".nuspec", XamarinFormsTargets);
+			var xamarinFormsTargets = Path.Combine (testDirectory, "..", "..", "..", "..", ".nuspec", XamarinFormsTargets);
 			if (!File.Exists (xamarinFormsTargets)) {
 				//NOTE: VSTS may be running tests in a staging directory, so we can use an environment variable to find the source
 				//	https://docs.microsoft.com/en-us/vsts/build-release/concepts/definitions/build/variables?view=vsts&tabs=batch#buildsourcesdirectory

build/steps/build-windows-test.yml

@@ -3,7 +3,9 @@ steps:
       displayName: 'Download build artifact win_build'
       inputs:
         downloadType: specific
-        itemPattern: '**/*.UnitTests/bin/$(BuildConfiguration)/*'
+        itemPattern: |
+          **/*.UnitTests/bin/$(BuildConfiguration)/*
+          **/*.Xaml.UnitTests/bin/$(BuildConfiguration)/**/*
         downloadPath: '$(Build.BinariesDirectory)'
         parallelizationLimit: 20
 
@@ -23,7 +25,7 @@ steps:
         testAssemblyVer2: |
           **/bin/$(BuildConfiguration)/Xamarin.Forms.Core.UnitTests.dll
           **/bin/$(BuildConfiguration)/Xamarin.Forms.Pages.UnitTests.dll
-          **/bin/$(BuildConfiguration)/Xamarin.Forms.Xaml.UnitTests.dll
+          **/bin/$(BuildConfiguration)/**/Xamarin.Forms.Xaml.UnitTests.dll
         searchFolder: '$(Build.BinariesDirectory)'
         pathtoCustomTestAdapters: '$(Build.BinariesDirectory)/testadapters/'
         codeCoverageEnabled: true