默认返回键和home键按键无声音解决

1, in phonewindowmanager.java->interceptKeyBeforeQueueing(): 
if (down && ((keyCode == KeyEvent.KEYCODE_HOME)||(keyCode == KeyEvent.KEYCODE_BACK)||....................)){ 
if(the sound is enable){ 
call the sound play. 
} 
} 
2, in AudioManager.java: 
playSoundEffect() if for play touch sound. 
querySoundEffectsEnabled() is for return whether touch sound is enable. 
3, effectType can be: 
* {@link #FX_KEY_CLICK}, 
* {@link #FX_FOCUS_NAVIGATION_UP}, 
* {@link #FX_FOCUS_NAVIGATION_DOWN}, 
* {@link #FX_FOCUS_NAVIGATION_LEFT}, 
* {@link #FX_FOCUS_NAVIGATION_RIGHT}, 
* {@link #FX_KEYPRESS_STANDARD}, 
* {@link #FX_KEYPRESS_SPACEBAR}, 
* {@link #FX_KEYPRESS_DELETE}, 
* {@link #FX_KEYPRESS_RETURN}, 
and I think in this issue, it should be:AudioManager.FX_KEY_CLICK.