[TIMOB-7363] iOS: flash on transition between splash and tab group when barImage is set

Actual behavior

The app launch, the splash screen comes up, when the splash goes and the tab group enter, there's a flash on the up bar, and then takes all the attributes (image and color).

Expected behavior

Smooth transition and no flashing when the splash screen goes off, and the tab group goes up.

Notes

It's almost an imperceptible thing, on big apps it's a little bit more notorious, I'm using a background for the bar, I'm attaching the png file, I'm notice that with the barImage propert, happens, without, it's totally imperceptible

Code

var tabGroup = Ti.UI.createTabGroup();

var win1 = Titanium.UI.createWindow({   
  title:'1', 
  backgroundColor:'#000',
  barImage:'navbar.png',
  barColor: '#AAA'
}); 

var tab1 = Titanium.UI.createTab({   
  icon:'KS_nav_views.png',  
  title:'1', 
  window:win1
});  

tabGroup.addTab(tab1);
tabGroup.open();