[image_picker] Update README for image_picker's retrieveLostData() to support multiple files (flutter#4336)

Author: reez12g

packages/image_picker/image_picker/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.8.4+1
+
+* Fix README Example for `ImagePickerCache` to cache multiple files.
+
 ## 0.8.4
 
 * Update `ImagePickerCache` to cache multiple files.

packages/image_picker/image_picker/README.md

@@ -62,14 +62,10 @@ Future<void> getLostData() async {
   if (response.isEmpty) {
     return;
   }
-  if (response.file != null) {
-    setState(() {
-      if (response.type == RetrieveType.video) {
-        _handleVideo(response.file);
-      } else {
-        _handleImage(response.file);
-      }
-    });
+  if (response.files != null) {
+    for(final XFile file in response.files) {
+      _handleFile(file);
+    }
   } else {
     _handleError(response.exception);
   }
@@ -78,8 +74,6 @@ Future<void> getLostData() async {
 
 There's no way to detect when this happens, so calling this method at the right place is essential. We recommend to wire this into some kind of start up check. Please refer to the example app to see how we used it.
 
-On Android, `retrieveLostData` will only get the last picked image when picking multiple images, see: [#84634](https://github.com/flutter/flutter/issues/84634).
-
 ## Migrating to 0.8.2+
 
 Starting with version **0.8.2** of the image_picker plugin, new methods have been added for picking files that return `XFile` instances (from the [cross_file](https://pub.dev/packages/cross_file) package) rather than the plugin's own `PickedFile` instances. While the previous methods still exist, it is already recommended to start migrating over to their new equivalents. Eventually, `PickedFile` and the methods that return instances of it will be deprecated and removed.

packages/image_picker/image_picker/pubspec.yaml

@@ -3,7 +3,7 @@ description: Flutter plugin for selecting images from the Android and iOS image
   library, and taking new pictures with the camera.
 repository: https://github.com/flutter/plugins/tree/master/packages/image_picker/image_picker
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+image_picker%22
-version: 0.8.4
+version: 0.8.4+1
 
 environment:
   sdk: ">=2.12.0 <3.0.0"