Set up Google Play for restricted user accounts i have a Samsung Galaxy Tab 4, running Android 5.0.2

I'm looking for a soluton to the following issue:

All of my family is using the tablet.
So i set up accounts for an admin, and personal accounts for me and my wife, linked to our Google email adresses.
I also set up restricted accounts for the kids. (They are not linked to any email as i remember)

Now one of the kids plays Clash of Clans. Game has been installed on the admin account, and authorization given so it can be used on the kids' restricted account.

It would be cool if the kids could use Google Play to save his game progress online.
But i'm struggling to find out how to set this up.
Currently, Google Play is installed and given access to the kid account.
From kid's account, i can launch Google Play, then launch CoC.
But the button "Google Play Sign In" in CoC does nothing. (It stays red, saying disconnected).
Seems it is still not recognized.

Do i need to have an email address for the kid?

How do i link it to the restricted account?
If this doesn't work, is there any other way i can achieve this?
Follow Following steps:-


First you have to make a gmail id for your kid.
Then open clash of clans and in settings use connect to supercell id follow this video https://m.youtube.com/watch?v=D7zX0kETazA] 
After connecting your kid account is connected to supercell id means id is backup online.
Now uninstall clash of clans from admin account and open your kid account and download again in that account from play store.
After install in his account just reconnect to supercell id by using newly created gmail.
They will send sign in code on Gmail open gmail app and account in which you have backup his account copy that code and enter in game.
Now all done nothing is connected to your admin account and clash of clans has ended support to Google play games. 


But Still If you want to connect to Google play use following steps:-


Create a new Gmail id then.
Open clash of clans and go to settings double click on Google play button.
An menu will pop up which shows you all accounts that you have in your device.
Just select newly created gmail which is created for kid all is done.
Uninstall clash of clans and logout admin account.
Open kid account download again From store and reconnect to Google play by double tapping on Google play in game settings and select newly created gmail account.


He will got his progress back any questions are most welcome.