Revert "Declare ReportQueue::Enqueue errors histogram"

This reverts commit 7c6ce31048b9d6b1204a8b1d7978c9d12be66067.

Reason for revert: Adding it to Browser.ERP. instead

Original change's description:
> Declare ReportQueue::Enqueue errors histogram
>
> This histogram will be populated when Enqueue is called from anywhere.
>
> Bug: b:258822636
> Change-Id: Iff3a9574393b74f99631f37f64a14c39855af58a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4035664
> Commit-Queue: Leonid Baraz <lbaraz@chromium.org>
> Reviewed-by: Owen Min <zmin@chromium.org>
> Auto-Submit: Leonid Baraz <lbaraz@chromium.org>
> Commit-Queue: Owen Min <zmin@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1073474}

Bug: b:258822636
Change-Id: Ibe87ad24df5518471d6460c2f19afe77279b7968
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4039042
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Owen Min <zmin@chromium.org>
Auto-Submit: Leonid Baraz <lbaraz@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1073662}