This reverts commit 1f8132a1.

Reason for revert: anglebug.com/3135

Bug: angleproject:3135

Original change's description:
> Vulkan: Reduce Default Descriptor Pool Max Sets
>
> The current value of kDefaultDescriptorPoolMaxSets is 2048, which
> allocates too much memory on a Pixel device, causing Android's low
> memory killer to terminate dEQP (leading to a test failure). This change
> reduces the value of kDefaultDescriptorPoolMaxSets to 128 to reduce the
> memory usage during the test. We suspect a later change may be required
> to dynamically grow the descriptor pools and update the recycling
> behavior.
>
> dEQP-EGL.functional.multicontext.non_shared_clear
>
> Bug: angleproject:3056
> Change-Id: I8a681b509823956a58d6c08f64a23203458e075e
> Reviewed-on: https://chromium-review.googlesource.com/c/1454280
> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
> Reviewed-by: Jamie Madill <jmadill@chromium.org>
> Commit-Queue: Tim Van Patten <timvp@google.com>

TBR=jmadill@chromium.org,timvp@google.com,syoussefi@google.com,syoussefi@chromium.org

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

Bug: angleproject:3056
Change-Id: Iff950425141eb5028c3660ba0567a9d29e691604
Reviewed-on: https://chromium-review.googlesource.com/c/1459256
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>