bufferqueues: Remove support for passing GL fences into BQs

These are going away since they're prone to cause deadlocks,
overcomplicate the API, and have been superceded by normal fd-based
fences (that can be derived from GL fences on most platforms).

Bug: 339705065
Flag: EXEMPT refactor
Test: old tests

Change-Id: I212f20ae77ddba234d888d1837c9e4935ccffa2f