I tried doing several answers for this question, but found out that the answers are not compatible for the latest Android Studio and Ubuntu 18.04.1.
My doubt is that Which directory I have to select for as Android SDK location?
Background: I Installed Android Studio from software center. It was shown Android SDK tool is missing at final step of installation. I ignored it and finished installation and proceeded till this step.
In Ubuntu 18, check this is the path:
/home/{your user name}/Android/Sdk
To set your path use this command below: