Android SDK Extras/ directory is missing

Question

I'm following the setup doc here to get started implementing in-App purchase for Android.

The docs reference the <sdk>/extras/google/play_billing/ directory and say to grab the IInAppBillingService.aidl file from that directory and add it to your project.

Despite having downloaded the latest SDK and associated files using Android SDK Manager, the Extras/ directory and this IInAppBillingService.aidl file are not present. Where can I find them?

(Frustrated side note: why are Google's Android docs so bad? Why do I need to copy a single file into my project instead of simply including a complete in-app-purchase jar?)

Edit:

Answer 1

I would make sure you don't have a duplicate SDK. Android Studio (if you're using it) comes with it's own Android SDK. If all else fails, I would probably uninstall that specific package and re-install it or a last resort of deleting the SDK and starting from scratch.