SpeechSynthesis.java: further simplify the setVoice method.

This renames `setVoiceByProperties` to the more consise `setVoice`
and removes the name parameter as this is not used -- the voice is
set by the language and gender parameters only.

android/src/com/reecedunn/espeak/TtsService.java

@@ -221,7 +221,7 @@ public class TtsService extends TextToSpeechService {
         mCallback.start(mEngine.getSampleRate(), mEngine.getAudioFormat(),
                 mEngine.getChannelCount());
 
-        mEngine.setVoiceByProperties(null, mMatchingVoice.name, gender);
+        mEngine.setVoice(mMatchingVoice.name, gender);
         mEngine.setRate(rate);
         mEngine.setPitch(pitch);
         mEngine.synthesize(text, text.startsWith("<speak"));