Enable H233

H233 (and H402) were temporarily disabled as part of the migration to
hacking 0.9. This patch fixes all H233 issues and re-enables
gating on them.

H402 has been removed in hacking
(I9426644fa708e9d5563abe04dc4ad656dbeb3656) so leave this one off as its
going away anyway.

Change-Id: Iae8f132c66c5e345dc2e9c2464f67609887c1475