[TIMOB-11366] iOS: StyledLabel module 1.5.2 doesn't have transparent background colour

*Problem* It is not possible to have a transparent background with the iOS module: StyledLabel version 1.5.2. It remains a white background. *Expected result* The StyledLabel should be able to have a transparent background. *Note* This question has also been asked here 2 months ago: https://marketplace.appcelerator.com/apps/790/questions/943?1603158271 This is despite having "iOS: The background of the styled label view is now transparent." in the v1.3 changelog. *Code*

var win = Ti.UI.createWindow({
	title : 'StyledLabel',
	backgroundColor: '#FF00FF'
});

var StyledLabel = require('ti.styledlabel');
var html = 'Testing 123';

var label = StyledLabel.createLabel({
	height : Ti.UI.SIZE || 'auto',
	top : 5,
	right : 5,
	bottom : 5,
	left : 5,
	html : html,
	backgroundColor: 'transparent'
});

win.add(label);
win.open();