I have created a flashable zip that works in an aftermarket recovery. It replaces the platform.xml file with modified file that has the necessary permission line to make the sd card writable now. That is the only thing changed. I added the under WRITE_EXTERNAL_STORAGE.
You need to be on a custom recovery. This update only applies to I9505G. If you do not have an S4 GOOGLE EDITION PHONE, then please disregard and move on.
Warning; You are flashing this at your own risk. I am not responsible for broken devices, deleted memory cards, phones thrown from raging, or WW3.
Download the flashable from here: http://d-h.st/Eif
Download the modified platform.xml to replace the original from here if you would rather push it: http://d-h.st/ooU
(this is not needed with zip, already included)
1. Place the zip the on your internal or external drive.
2. Reboot to your custom recovery, ie ( twrp, cwm)
3. Create a backup, have a restore point if it does not work.
4. Wipe dalvik and cache
5. Install the zip file
6. Wipe the dalvik and cache just to be sure.
7. Reboot phone.
Test to make sure it worked by using any file explorer, ie(solid explorer, root explorer, etc.) and creating a new folder, text document, or whatever. Do this through the phone, not a p.c. If it does not work, reboot to recovery, restore back to previous point and let me know asap.