Restore a state that was previously returned by LocalActivityManager.SaveInstanceState. This adds to the activity group information about all activity IDs that had previously been saved, even if they have not been started yet, so if the user later navigates to them the correct state will be restored.

Note: This does not change the current running activity, or start whatever activity was previously running when the state was saved. That is up to the client to do, in whatever way it thinks is best.

[Android Documentation]