Fix the security related API change for PreferenceActivity

Bug: 10118761
Change-Id: I63501d6c2b5f561d7ab8b7362498665d805d5e1e
diff --git a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
index ad68f8c..c899507 100644
--- a/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
+++ b/java/src/com/android/inputmethod/latin/settings/SettingsActivity.java
@@ -16,6 +16,8 @@
 
 package com.android.inputmethod.latin.settings;
 
+import com.android.inputmethod.latin.utils.FragmentUtils;
+
 import android.content.Intent;
 import android.preference.PreferenceActivity;
 
@@ -36,6 +38,6 @@
     // TODO: Uncomment the override annotation once we start using SDK version 19.
     // @Override
     public boolean isValidFragment(String fragmentName) {
-        return fragmentName.equals(DEFAULT_FRAGMENT);
+        return FragmentUtils.isValidFragment(fragmentName);
     }
 }