title: ViewModel gets cleared when "do not keep activity" dev option is turned on
body: <p>Here is my setup
  1. Main Activity - Contains MainFragment
  Mainfragment - Has MainFragViewModel</p>
  
  <p>Repro - 
  1. Turn on do not keep activities in developer setting.
  2. Launch application. 
  3. Press home. </p>
  
  <p>Now due to our setting following activities happened as the app went into backgroud.
  1. Fragment View model - onCleared()  [UNEXPECTED, Because system is killing the fragment, and app process is not killed.]
  2. Fragment destroyed [Expected]
  3. Main Activity destroyed - isFinishing = false (that means framework has knowledge who is killing) [Expected]
  4. Application didn't get destroyed [Expected]</p>
  
  <p>Now start the app again from the background apps cards. and following happened.
  1. Main Acitivity - onCreate(bundle != null) [Expected. It also delivered bundle! all good]
  2. Fragment created [Expected - bundle got delivered. i.e not null]
  3. FragmentViewModel instance got created [UnExpected!! as the viewmodel should have survived. Because we didn't pop the fragment. It was killed by the system due to the dev setting]</p>
  
  <p>This behavior breaks my design, and in order to make my apps working ok on developers phone who may turn do not keep activity. I have to save the information in Bundle!! </p>
  
  <p>What am I missing? What are your possible solutions ?</p>