Move dequeue-buffer-and-wait out-of-line

The dequeueBuffer_DEPRECATED function also waits for the buffer fence,
so we can just call that. That way the wait call is compiled into our
code (instead of driver code) and we can see/modify it for debugging.

Bug: 7217641
Change-Id: Ie2ea85ed1543a4ff7986d0162aee773e93591309