[build] Fix Java.Interop utilities directory

`Configuration.Java.Interop.Override.props` is copied into 
`external/Java.Interop`, and thus `$(MSBuildThisFileDirectory)` will
be `external/Java.Interop`, *not* the `xamarin-android` topdir.

Consequently, `class-parse` and company will be built into
`external/Java.Interop/bin/$(Configuration)/lib/mandroid`, which is
*not* the correct directory.

Fix the `$(UtilityOutputFullPath)` value so that it places
`class-parse.exe` and company into `xamarin-android`'s
`bin/$(Configuration)/lib/mandroid`, not `Java.Interop`'s.

Author: jonpryor

Configuration.Java.Interop.Override.props

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <UtilityOutputFullPath>$(MSBuildThisFileDirectory)bin\$(Configuration)\lib\mandroid\</UtilityOutputFullPath>
+    <UtilityOutputFullPath>$(MSBuildThisFileDirectory)..\..\bin\$(Configuration)\lib\mandroid\</UtilityOutputFullPath>
   </PropertyGroup>
 </Project>