[TIMOB-17272] Android: Unable to toggle the background image of a window when background color is null

var _window = Titanium.UI.createWindow({  
    title:'ToggleBG',
    backgroundColor: 'white'
});

_window.modal = false ;
		_window.exitOnClose = false ;
		    
		var btn1 = Ti.UI.createButton({
		    top:10,
		    title:'TOGGLE BGIMAGE'
		});
		var btn2 = Ti.UI.createButton({
		     
		    title:'TOGGLE BGCOLOR'
		});
		 
		_window.add(btn1);
		_window.add(btn2);		 

		 
		var hasImage = false;
		var hasColor = false;
		 
		btn1.addEventListener('click',function(){
		    if(hasImage == false) {
		        _window.backgroundImage = 'KS_nav_views.png';
		    }
		    else {
		        _window.backgroundImage = null;
		    }
		    hasImage = !hasImage;
		});
		btn2.addEventListener('click',function(){
		    if(hasColor == false) {
		        _window.backgroundColor = 'orange';
		    }
		    else {
		        _window.backgroundColor = null;
		    }
		    hasColor = !hasColor;
		});
_window.open();