We're currently adding an MVP for setup/uninstall flow for Crostini. This involves a preference called kCrostiniEnabled (aka crostini.enabled). We may eventually want to split this into a preference and an installation-status. There will also need to be an enterprise policy for Crostini.

How and when the preference is changed, what the corner cases are, and how it interacts with the policy will need to be considered properly. Also need to add unit tests for these behaviors.

Related:
https://bugs.chromium.org/p/chromium/issues/detail?id=833125
https://bugs.chromium.org/p/chromium/issues/detail?id=822504