Fix missing string reference of spellchecker.xml

This is a followup of I8dea5393ad.

Change-Id: I311c50cf8205298f20694e068bb9a4b661df8a8b
diff --git a/java/res/xml/spellchecker.xml b/java/res/xml/spellchecker.xml
index 813319c..13e6132 100644
--- a/java/res/xml/spellchecker.xml
+++ b/java/res/xml/spellchecker.xml
@@ -21,7 +21,7 @@
      for the spell checker -->
 
 <spell-checker xmlns:android="http://schemas.android.com/apk/res/android"
-        android:label="@string/aosp_spell_checker_service_name"
+        android:label="@string/spell_checker_service_name"
         android:settingsActivity="com.android.inputmethod.latin.spellcheck.SpellCheckerSettingsActivity">
     <subtype
             android:label="@string/subtype_generic"