Add note on creating new ViewModel instances

Author: dturner

app/src/main/java/com/example/nav3recipes/passingarguments/injectedviewmodels/InjectedViewModelsActivity.kt

@@ -82,6 +82,14 @@ class InjectedViewModelsActivity : ComponentActivity() {
                     }
                     entry<RouteB> { key ->
                         val viewModel = hiltViewModel<RouteBViewModel, RouteBViewModel.Factory>(
+                            // Note: We need a new ViewModel for every new RouteB instance. Usually
+                            // we would need to supply a `key` String that is unique to the
+                            // instance, however, the ViewModelStoreNavEntryDecorator (supplied
+                            // above) does this for us, using `NavEntry.contentKey` to uniquely
+                            // identify the viewModel.
+                            //
+                            // tl;dr: Make sure you use rememberViewModelStoreNavEntryDecorator()
+                            // if you want a new ViewModel for each new navigation key instance.
                             creationCallback = { factory ->
                                 println("Creating viewModel for $key")
                                 factory.create(key)