Guys! Follow any update from the Intel XDK. Recently, it has announced that the third party Admob API is already available at github.
Something to note is that:
Because this app uses a Cordova plugin, it can only be built using the Cordova build targets. Attempting to use the "legacy" build targets will not work.Meaning, when performing the "Build" action from the Intel XDK IDE, you have to select the Android from the "Cordova" section, instead of the Legacy part, as shown in the picture below: