Unfortunately, the patching system doesn't work with Android. So you'll have to download the entire update and then install it as you did the first time (it will ask if you want to update the game - say yes).
Your saves are automatically transferred between versions so you don't need to do anything.
Only caveat is: DO NOT DELETE THE GAME! There are no cloud saves (because Google Play won't allow CK on their store) so deleting the game without backing up your saves first means they're gone forever.
Hope that helps :)