android: limit max speech rate to 449 WPM

this is the maximum espeak-ng's speech rate without using libsonic

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

     public void testDefaultRate()
     {
         SpeechSynthesis synth = new SpeechSynthesis(getContext(), mCallback);
-        defaultRateTest(300, 450, synth); // clamped to maximum value
+        defaultRateTest(300, 449, synth); // clamped to maximum value
         defaultRateTest(200, 350, synth);
         defaultRateTest(100, 175, synth); // default value
         defaultRateTest( 50,  87, synth);
     public void testEspeakRate()
     {
         SpeechSynthesis synth = new SpeechSynthesis(getContext(), mCallback);
-        espeakRateTest(500, 450, synth); // clamped to maximum value
+        espeakRateTest(500, 449, synth); // clamped to maximum value
         espeakRateTest(400, 400, synth);
         espeakRateTest(200, 200, synth);
         espeakRateTest(175, 175, synth); // default value

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

     }
 
     /** Speech rate. */
-    public final Parameter Rate = new Parameter(1, 80, 450, UnitType.WordsPerMinute);
+    public final Parameter Rate = new Parameter(1, 80, 449, UnitType.WordsPerMinute);
 
     /** Audio volume. */
     public final Parameter Volume = new Parameter(2, 0, 200, UnitType.Percentage);