[shared_preferences] Fix example in readme for mocking values (#4411)

This fixes the example for mocking values in the readme of shared_preferences.
After the NNBD migration mock values can only be of type Object.
diff --git a/packages/shared_preferences/shared_preferences/CHANGELOG.md b/packages/shared_preferences/shared_preferences/CHANGELOG.md
index cc29dd9..d8c4331 100644
--- a/packages/shared_preferences/shared_preferences/CHANGELOG.md
+++ b/packages/shared_preferences/shared_preferences/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.0.11
+
+* Corrects example for mocking in readme.
+
 ## 2.0.10
 
 * Removes obsolete manual registration of Windows and Linux implementations.
diff --git a/packages/shared_preferences/shared_preferences/README.md b/packages/shared_preferences/shared_preferences/README.md
index e51ddea..46d022f 100644
--- a/packages/shared_preferences/shared_preferences/README.md
+++ b/packages/shared_preferences/shared_preferences/README.md
@@ -42,5 +42,6 @@
 You can populate `SharedPreferences` with initial values in your tests by running this code:
 
 ```dart
-SharedPreferences.setMockInitialValues (Map<String, dynamic> values);
+Map<String, Object> values = <String, Object>{'counter': 1};
+SharedPreferences.setMockInitialValues(values);
 ```
diff --git a/packages/shared_preferences/shared_preferences/pubspec.yaml b/packages/shared_preferences/shared_preferences/pubspec.yaml
index 156e2e2..a16cd20 100644
--- a/packages/shared_preferences/shared_preferences/pubspec.yaml
+++ b/packages/shared_preferences/shared_preferences/pubspec.yaml
@@ -3,7 +3,7 @@
   Wraps NSUserDefaults on iOS and SharedPreferences on Android.
 repository: https://github.com/flutter/plugins/tree/master/packages/shared_preferences/shared_preferences
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+shared_preferences%22
-version: 2.0.10
+version: 2.0.11
 
 environment:
   sdk: ">=2.14.0 <3.0.0"