Update Versions.props

Author: psfinaki

eng/Versions.props

@@ -94,7 +94,7 @@
     <MicrosoftVisualStudioShellPackagesVersion>17.10.40152</MicrosoftVisualStudioShellPackagesVersion>
     <VisualStudioProjectSystemPackagesVersion>17.10.526-pre-g1b474069f5</VisualStudioProjectSystemPackagesVersion>
     <MicrosoftVisualStudioThreadingPackagesVersion>17.10.41</MicrosoftVisualStudioThreadingPackagesVersion>
-    <MicrosoftBuildVersion>17.12.6</MicrosoftBuildVersion>
+    <MicrosoftBuildVersion>17.12.0-preview-24426-07</MicrosoftBuildVersion>
     <!-- Roslyn packages -->
     <MicrosoftCodeAnalysisEditorFeaturesVersion>$(RoslynVersion)</MicrosoftCodeAnalysisEditorFeaturesVersion>
     <MicrosoftCodeAnalysisEditorFeaturesTextVersion>$(RoslynVersion)</MicrosoftCodeAnalysisEditorFeaturesTextVersion>