[android] skip code generation for Mono.Android
[android] skip code generation for Mono.Android

- We need to skip code generation for C# class subclassing anything in
Mono.Android.dll
- Next step will be to generate the Java source from Xamarin.Android
via the `GenerateJavaStubs` MSBuild task

mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,mono/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000,jonathanpeppers/Embeddinator-4000