Has now been reproduced and fixed. Unfortunately, we're just about to do a release, so this will now be in the next one.
http://bugs.yoyogames.com/view.php?id=27957
In the meantime, you can add the correct package name in the [project save folder]\options\android\options_android.yy file and then build your package. You can then still open Game Options > Android fine, but don't click in any of the package name fields or the IDE will complain about the name and you'll have to hand-edit the file again.