title: Shared viewmodel between fragments, without scoping to the activity?
body: <p>Using the new Navigation Architecture Component, I've got a single activity as a navhost with multiple fragments for my screens. Right now I have an EditProfileFragment where the user can click a button and another fragment opens, with a list of countries to choose from. Let's say I want to share the result of that country selection back to the EditProfileFragment. The general idea is that I'll have a single EditProfileViewModel for all "edit profile" actions.</p>
  
  <ol>
  <li><p>How do I share the selected country between those fragments? I'm thinking using a shared viewmodel, but I'm hesitant scoping it to the activity because I don't want it to persist when the user completes the "edit profile" flow.</p></li>
  <li><p>Are there any other clean/recommended approaches I should consider? Maybe a singleton that temporarily holds that value?</p></li>
  </ol>