checkbox custom icon

[pegahph]

hi, adding a custom icon for the checkbox causes these warnings which are so annoying:
. React does not recognize the isSelected prop on a DOM element.
. React does not recognize the isIndeterminate prop on a DOM element.
. React does not recognize the disableAnimation prop on a DOM element
these warnings are reasonable due to the fact that the icon has CheckboxIconProps type which contains these props but custom icons don't support them!