We want a finch config to control the Crostini UI rollout.
There is already a chrome flag chrome://flags#enable-experimental-crostini-ui that's used to turn on Crostini UI manually by the user.
The new Finch config will be a separate one. It'll control the release of the Crostini UI without the need for a manual flag flip.
As a result, the Crostini UI feature should be on when either method is enabling it.