Just noticed the other day that if you try and merge the two latest version of the Admob and Google Play Services plugins you will get an error ‘Build failure, Unable to convert classes into dex format.’ This error is due to Google putting the Admob libraries into the Google Play Services library effectively doubling up the classes and causing mayhem (do do dop a lotta Mayhem, thanks Emelda May).
Luckily the fix is nice and easy, just remove the Ads folder from the google play jar (thanks to Prime31 for this idea).
Here is the amended jar, just overwrite the existing one in the Plugins/Android folder. Use this one and not the Prime31 version since it looks like we are using different api versions.
I will of course merge this change into the next version of the Google Play Plugin so this should be a non-issue moving forward. The new Admob Plugin version using the libraries inside the Google Play library is on hold until Google fix them (they seem buggy).