Hey, guys! <img src="{SMILIES_PATH}/icon_e_biggrin.gif" alt=":D" title="Very Happy">
I just wanted to share the info with you that it works for me.
I spent around 2 hours to give it a try.
I used the built-in Admob Construct 2 plugin, and followed steps from their documentation.
I gave a look at this tutorial: https://youtu.be/2Lvohs8_7cQ - Which is just basic, except that the right Plugin ID to add to your XDK project is cordova-plugin-ad-admob shown in the video, and not the one from C2 documentation.
Then I set up the xdk project ready for production, build it and import it into PhoneGap.
In PhoneGap, I built the app for production as well. Download the .apk, install it manually on my Android (Motorola G running version 5.1 of Android), and tadaaa... Ad is showing. <img src="{SMILIES_PATH}/icon_cool.gif" alt="8-)" title="Cool">
Hope this help!
Tomorrow I will upload the game to Play Store and iOS for Beta testing, and I'll let you know if it works. Hope so.