Alert style constructor function
The backgroundColor parameter sets the background color.
The separateColor parameter sets the button's separate color.
The borderRadius parameter sets alert's borderRadius. default is 8
The titleStyle parameter sets alert title text style.
The titleTextAlign parameter sets alignment of the title.
The messageStyle parameter sets alert desc text style.
The messageTextAlign parameter sets alignment of the desc.
The constraints parameter sets Alert size.
The alertPadding parameter sets alert area padding.
The alertAlignment parameter sets alert area alignment.
