Re-add check for bold bit in Black weight.
Re-add check for bold bit in Black weight.

Check removed in ca851298519eb19c3c89cc2b3a6c0770b04257a4.

It may or may not be standard practice, but Roboto has previously set
the bold bit for its Black weight so we'll keep it this way to avoid
regression.

anthrotype/roboto,googlefonts/roboto,moyogo/roboto,googlefonts/roboto,moyogo/roboto,anthrotype/roboto