Added Q&A about ViewModel

README.md

@@ -287,7 +287,9 @@ Cheat Sheet for Android Interviews
    * Basics of [ViewModel](https://developer.android.com/reference/android/arch/lifecycle/ViewModel): A ViewModel is LifeCycle-Aware. In other words, a ViewModel will not be destroyed if its owner is destroyed for a configuration change (e.g. rotation). The new instance of the owner will just re-connected to the existing ViewModel. So if you rotate an Activity three times, you have just created three different Activity instances, but you only have one ViewModel.
    * So the common practice is to store data in the ViewModel class (since it persists data during configuration changes) and use OnSaveInstanceState to store small amounts of UI data.
    * For instance, let’s say we have a search screen and the user has entered a query in the Edittext. This results in a list of items being displayed in the RecyclerView. Now if the screen is rotated, the ideal way to prevent resetting of data would be to store the list of search items in the ViewModel and the query text user has entered in the OnSaveInstanceState method of the activity.</br>
-
+
+ * <b>What happens to ViewModels and onSaveInstanceState data when the process is killed?</b></br>
+   * ViewModels only survive configuration change-related destruction; they do not survive the process being stopped. But in the case of onSaveInstanceState, its saved in cache which can be retained after.
 
 * <b>Mention two ways to clear the back stack of Activities when a new Activity is called using intent</b></br>
    * The first approach is to use a FLAG_ACTIVITY_CLEAR_TOP flag. The second way is by using FLAG_ACTIVITY_CLEAR_TASK and FLAG_ACTIVITY_NEW_TASK in conjunction.</br>