CategoryAttribute is places on several properties in ActivityAttribute

[marek-safar]

This seems unnecessary at least for netcore builds and based on @jonathanpeppers look it does not seem to work. It'd be better to clean this up not do pull additional unnecessary dependencies.

https://github.com/xamarin/xamarin-android/blob/master/src/Xamarin.Android.NamingCustomAttributes/Android.App/ActivityAttribute.cs#L56

[jonathanpeppers]

Context:

• d548ec9
• (nice GIF): Annotate attribute members with resource completion hint #2862

I asked the IDE team if anyone knows if it should work or not. Not heard back yet.