SF: Remove SurfaceFlingerFactory::createBufferQueue

This enabled tests to set up mock BQs for testing. However the tests
were largely uninteresting and incredibly complex to maintain. We're
also removing the ability to create BQs anywhere, so this is not really
a great way to deal with them.

Bug: n/a
Flag: EXEMPT test change
Test: updated tests succeed
Change-Id: I7cfe47e2b93e8cb147e204d2349d67cd2e46449e