Correct parentActivity example in Activity Element docs.

Bug:
https://code.google.com/p/android/issues/detail?id=74474

Change-Id: I09d07a69d6aa0087e60443ed819541e979012948
(cherry picked from commit 0b54c6c74a)

docs/html/guide/topics/manifest/activity-element.jd

@@ -714,7 +714,7 @@ For example:</p>
 &lt;activity
     android:name="com.example.app.ChildActivity"
     android:label="@string/title_child_activity"
-    android:parentActivityName="com.example.myfirstapp.MainActivity" >
+    android:parentActivityName="com.example.app.MainActivity" >
     &lt;!-- Parent activity meta-data to support API level 4+ -->
     &lt;meta-data
         android:name="android.support.PARENT_ACTIVITY"