feat(android): navBarColor for Window

[m1ga]

Android:
Add navBarColor property to change the navigation bar color using code. Since we use navBarHidden I've used the same name with color at the end instead of navigationBarColor.

Current way:
Set the color in your theme.

Example code:

Normal Window:

var win = Ti.UI.createWindow({
	navBarColor:"#0f0"
});
setTimeout(function(){
	win.navBarColor = "#f00";
},2000)

win.open();

NavigationWindow:

var win2 = Titanium.UI.createWindow({
		navBarColor:"#0f0"
});

var win1 = Titanium.UI.createNavigationWindow({
    window: win2
});

var win3 = Titanium.UI.createWindow({
		navBarColor:"#f00"
});

var button = Titanium.UI.createButton({
    title: 'Open Window'
});
button.addEventListener('click', function(){
    win1.openWindow(win3, {animated:true});
});

win2.add(button);
var button2 = Titanium.UI.createButton({
    title: 'Close Window'
});
button2.addEventListener('click', function(){
    win1.closeWindow(win3, {animated:false}); 
});

win3.add(button2);
win1.open();

[cb1kenobi]

CR's, but didn't test. LGTM!

[prashantsaini1]

Good to merge!