Revert "Reland "[dawn] Switch indirect dispatch validation to use immediates""

This reverts commit fc5539cb93cb699c2f5f8a1d68d24331cf401bf0.

Reason for revert: https://crbug.com/558141650

Original change's description:
> Reland "[dawn] Switch indirect dispatch validation to use immediates"
>
> This is a reland of commit 104068a1a6c0bacad1e9896f18a7c558f82f5444
>
> New changes are the use of a designated initializer for Params and the
> update to use the spanified APISetImmediates entrypoint.
>
> Original change's description:
> > [dawn] Switch indirect dispatch validation to use immediates
> >
> > Change the indirect dispatch validation shader to use immediates instead
> > of a uniform buffer.
> >
> > Fix: 488346117
> > Change-Id: Ib0804f399bd387bcd93b5540490b566d57ff88d4
> > Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/294716
> > Commit-Queue: Corentin Wallez <cwallez@chromium.org>
> > Reviewed-by: Corentin Wallez <cwallez@chromium.org>
>
> Change-Id: I9787cef71529e916f06cf65e2a02726dfc5b85b9
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/298275
> Reviewed-by: Shaobo Yan <shaoboyan@microsoft.com>
> Reviewed-by: Loko Kung <lokokung@google.com>
> Commit-Queue: Corentin Wallez <cwallez@chromium.org>

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

Bug: 558141650
Change-Id: I667ca2e0d2b3c38fc18cb90090ce6203d6eb6801
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/340175
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Shaobo Yan <shaoboyan@microsoft.com>
Reviewed-by: Shaobo Yan <shaoboyan@microsoft.com>