[vulkan] Use FIDL for QEMU pipe stream on Fuchsia.

This is needed as POSIX IO support on Fuchsia is being
deprecated. Benchmarks also show that FIDL API is ~ 25X
faster for large transfers to host so this will result
in a performance improvement.

Change-Id: Iedda195ef0931c1f561f4b60ab811d968a83c0e8
3 files changed