If you are able to download an update of Android Studio, but after it restarts nothing happens, check out the following example:
cd ~/android-studio
bin
subfolder:
cd bin
studio.sh
file has run permissions:
chmod +x studio.sh
./studio.sh
After that Android Studio will find the patch and install it. Then you may close Android Studio and run it the regular way (whatever way you prefer, I run it from Launcher pad).