This reverts commit 326f128b.

Reason for revert: Fails of Mali platform. See bug:

Bug: angleproject:5544

Original change's description:
> Vulkan: Prefer host cached memory for Buffers
>
> This improves perf because vertex data upload uses host visible memory,
> and uncached memory can be slow.
>
> Test:
>
> Android on Windows with 1080Ti:
> glmark2 [build] vbo=false 265 -> 3900 fps
>
> Bug: angleproject:5515
> Change-Id: Ib75582bbdb4ca4a22d3a121c7b477a23a8a809ef
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2615742
> Commit-Queue: Lingfeng Yang <lfy@google.com>
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Reviewed-by: Tim Van Patten <timvp@google.com>

TBR=geofflang@chromium.org,lfy@google.com,doughorn@google.com,timvp@google.com,jmadill@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: angleproject:5515
Change-Id: I59695b1981b43471dbd309d4e859bae7a4821969
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2627604Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Lingfeng Yang <lfy@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>