Reland "Import dcheck_always_on.gni in linux toolchain"

This is a reland of commit d5cea6cb3069d62596fb8b33a5f01df901ebb976

The original issue why the original change was reverted is now fixed:

Requiring //build/config/dcheck_always_on.gni resulted in requiring gclient_args.gni file that is normally auto-generated by gclient. But it revealed a bug in the gclient where the file would not be generated if the .glient config contains more than a single solution (which was the case for the DevTools project).

Fixed in https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3702359

Original change's description:
> Import dcheck_always_on.gni in linux toolchain
>
> To prevent a warning that the build argument dcheck_always_on has no
> effect.
> The arg was introduced in crrev.com/c/3665998
>
> Change-Id: Id343fa73418d7af6733f86a81d5bd3a3999ae321
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3695253
> Reviewed-by: Sven Zheng <svenzheng@chromium.org>
> Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
> Commit-Queue: Alex Rudenko <alexrudenko@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1012362}

Change-Id: I71d5e5673e7b4b8640b29a06d62d41fdbe228b72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3717827
Commit-Queue: Alex Rudenko <alexrudenko@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1017050}
NOKEYCHECK=True
GitOrigin-RevId: 8e4786fb941801e755c515f0ae3347d0da9082bf
1 file changed