Yes, you can configure Android Studio to automatically add a new line at the end of a file.
File | Settings... menu, then Editor under IDE Settings, then check the Ensure line feed at file end on Save option box.
This will only take effect on freshly edited files after the setting has been enabled.
UPDATE
On newer versions of Android Studio, the preference location has changed to
File > Preferences > Editor > General > Ensure line feed at file end on Save