TextToSpeechTestCase: use isTtsLangCode to check TextToSpeech.LANG_*

android/eSpeakTests/src/com/reecedunn/espeak/test/TextToSpeechTestCase.java

 
 import java.util.Locale;
 
+import static com.reecedunn.espeak.test.TtsMatcher.isTtsLangCode;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.*;
 
                 Log.d("TextToSpeechTestCase", "setUp: available = " + available);
             }
 
-            assertThat(available, is(TextToSpeech.LANG_COUNTRY_VAR_AVAILABLE));
+            assertThat(available, isTtsLangCode(TextToSpeech.LANG_COUNTRY_VAR_AVAILABLE));
         }
         catch (Exception e)
         {