Fixing bug 2418114. Added a check to make sure the TTS sample string for

a language-country combination is available before trying to use it.

src/com/android/settings/TextToSpeechSettings.java

@@ -425,7 +425,9 @@ public class TextToSpeechSettings extends PreferenceActivity implements
         // update the demo string
         mDemoStringIndex = mDefaultLocPref.findIndexOfValue(mDefaultLanguage + LOCALE_DELIMITER
                 + mDefaultCountry);
-        mDefaultLocPref.setValueIndex(mDemoStringIndex);
+        if (mDemoStringIndex > -1){
+            mDefaultLocPref.setValueIndex(mDemoStringIndex);
+        }
     }
 
     /**