[Bug] 'apple-touch-icon' and 'mask-icon' being flagged as invalid values

I'm pretty sure it was added recenty, but this should be a bug right? Even MDN which the [rule's page](https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/no-invalid-html-attribute.md) tells us to check mentions how iOS doesn't use `icon`, but instead `apple-touch-icon`. `mask-icon` is also used by them on Safari pinned tabs.