Add java-interop.jar to the Xamarin.Android install set #1375

The Android Designer currently has it's own copy of many of our core types, which means if we alter this set of core types, things break.

java-interop.jar, part of the Java.Interop build, already contains many of these types.

We should update the Xamarin.Android SDK build to install java-interop.jar, and ensure that all types which the Android Designer requires are within that file.