Hi, you can still export your C2 projects to Android. Don't worry. Just do all the steps you did before (export to Cordova, open in Intel XDK, sign your APK and add the exact same plugins you added before, upgrade the App Version Code, etc...). Now, when everything is done, instead of building your game with the Intel XDK, you can retrieve a zip containing all the information needed. After that, sign in in Adobe Phonegap Build (free version allows you to have one project opened at the time) and upload that zip file. Enter your key password and click "rebuild" to be able to download an APK file that you can submit to the Play Store.
To sum it up, you can keep doing the same steps as you did before with the Intel XDK and the only change is that now, you have to build the APK elsewhere (for example Phonegap Build, which has a very very similar build system as Intel's old one).
You should be able to keep using the exact same Plugins that you used before when you exported with Intel XDK, but, why do you use a third party Plugin? What is the advantage over the official Admob Plugin?