I'm playing Pokemon Clover for the first time and have a quick question about the dream pill.

So I want to use Serene Grace Chanolour on my team, and I know I can use the dream pill to get it, but to my knowledge, Pokemon have two hidden abilities in Clover. Can I be sure that once I use the dream pill I can get Serene Grace? Is it a coin flip between the 2 HAs when I use it or is it dependent on the ability Clovour already has?

I'm asking because I plan on REing for the right nature and EV training it, so I just don't want to get to Triport only to find out I can't get Serene Grace.

Thanks in advance, anons.