Correspond to the security related API change for PreferenceActivity

Bug: 10118761
Change-Id: Ia7d1c6c526dae849f447c26387e96a4fb4d6042f
diff --git a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
index 6c38186..ad68f8c 100644
--- a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
+++ b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
@@ -32,4 +32,10 @@
         intent.putExtra(EXTRA_NO_HEADERS, true);
         return intent;
     }
+
+    // TODO: Uncomment the override annotation once we start using SDK version 19.
+    // @Override
+    public boolean isValidFragment(String fragmentName) {
+        return fragmentName.equals(DEFAULT_FRAGMENT);
+    }
 }