How to create JavaDoc using Android Studio without R and BuildConfig?

RocketSpock’s answer is almost there, but not quite (as of this writing). I can’t comment yet, so I’ll describe the process I used to exclude R.java and BuildConfig.java from my Android library’s Javadoc in Android Studio 1.2.2. There’s basically an extra dialog that will come in very handy:

1. Open menu option Tools --> Javadoc.

2. Select Custom scope. It’s not necessary to select anything from
   the drop-down menu yet.

3. Click the ... icon to open the Scopes dialog.
4. Add a new custom scope with the green + icon. Give it a
   descriptive name if you wish.
5. In Production Classes (not Library Classes, since those are
   imports) navigate to the module(s) you wish to generate Javadoc for,
   and select any individual Java files you wish to include. In your
   case, you probably want to select an entire module but
   manually exclude R.java and BuildConfig.java. When you’re done, Click OK to exit the Scopes dialog.
6. In the Specify Generate JavaDoc scope dialog, if your new scope is
   not selected in the Custom scope dropdown menu, select it now, as
   well as any other additional options including output directory.
7. Finally, click OK to generate your Javadoc.