Is it possible to create a Droplet for Contact Sheet in Photoshop CC

I see no reason why you would not be able to create a droplet for contact sheet II. You create a droplet from menu File>Automate>Create Droplet... Did you record an action for your droplet?

In the Create Droplet Dialog you set where to saver the droplet and name it. You Create it to play an Action.

So you record an Action that uses Photoshop Plug-in Contact Sheet II.  Its in  menu File>Automate>Contact Sheet II...

In the Contact Sheet II Dialog you set  up how Contact Sheet II should run.  The Plug-in will store those settings in the Action step being recorded.  When you Play the Action the Settings will be sent the the Contact Sheet Plug-in the plug-in will bypass displaying its Dialog abs user the passed settings. So make sure you record the plug-in the way you want it to run.  The Setting to use are recorded into the Action step.  If you use the Action or droplet made from the action. the Setting stored in the Action Step are used by the plug-in Contact Sheet II.   Contact Sheet cam be recorded toe process folders or files and add open files. You may have to test to see if you can record a Contact Sheet II step the works the way you would want  the droplet work the way you want it to.