Could not run Android Studio on my Mac OS Yosemite. Error: The following SDK component was not installed: sys-img-x86-addon-google_apis-google-21

Try this that is suggested in the link you mention:

Open the terminal and execute these 2 commands:

cd /Applications/Android\ Studio.app/Contents/MacOS/
sudo ./studio

It seems that you need to run it as administrator the first time you launch it. I haven't tried that but looks promising.

Run sudo /Applications/Android\ Studio.app/Contents/MacOS/studio