Remove bc, bc2 from pbi,cpi,xd

Pass the bool coder to be used explicitly. This avoids cases where two
different bool coders can be addressed from the same function. Also be
more consistent with bool coder variable naming, start to standardize
on 'bc'.

Change-Id: I1c95e2fdbe24ebe8c0f84924daa1728e3b054a31