`font-family` seems to be ignored

Seems that, despite providing a `font-family` attribute in our Stylesheets, with a font that is definitively installed and active on my Mac, the font is apparently not used in the rendered screenshots.

For example, even when I edit the `style.css` file used in WPAndroid to set `font-family: 'Webdings'` and `font-color: red`, I can see that the text appears red (so the stylesheet has been found and used) but still in the default font (or at least a font that legible and definitively not Webdings)