BufferQueues: clean up constructors for GLConsumer and CpuConsumer

These currently use flags that muddy up client code. We've added nice
new *::create methods, so lets use those and clean
things up.

BYPASS_IGBP_IGBC_API_REASON=warren buffers

Bug: 398822412
Flag: EXEMPT refactor
Test: builds, presubmit

Change-Id: If86b22a6ddaed044afdaa06a2e2fb1c7a79ba941