This change basically moves the singaling of the surface acquire event into the gpu driver, eliminating the VkQueueWaitIdle on surface submission
This change depends on https://skia-review.googlesource.com/c/25641/ so do not submit until Flutter has rolled Skia past that point
This version does not recycle buffers. It is meant only as an initial solution,
and the proper buffer recycling logic has been broken out into a separate change
