Turn off personalization default settings

Because the previous personalization settings default value was on,
this CL changes the preference key of the personalization settings.

Bug: 10587358
Change-Id: I80233e8af4b532d8c67d8fb184c2865862bb35dd
diff --git a/java/res/xml/prefs.xml b/java/res/xml/prefs.xml
index a39ce4a..c9be449 100644
--- a/java/res/xml/prefs.xml
+++ b/java/res/xml/prefs.xml
@@ -90,11 +90,11 @@
             android:entries="@array/prefs_suggestion_visibilities"
             android:defaultValue="@string/prefs_suggestion_visibility_default_value" />
         <CheckBoxPreference
-            android:key="pref_key_use_personalized_dicts"
+            android:key="pref_use_personalized_dicts"
             android:title="@string/use_personalized_dicts"
             android:summary="@string/use_personalized_dicts_summary"
             android:persistent="true"
-            android:defaultValue="true" />
+            android:defaultValue="false" />
     </PreferenceCategory>
     <PreferenceCategory
         android:title="@string/gesture_typing_category"