Revert "Default disallow deprecated namespaces in Chromium"

This reverts commit e6fb7d69dad1760b424731a5947918d9b39c2288.

Reason for revert: nearby still using deprecated namespaces

Bug: webrtc:42232595
Original change's description:
> Default disallow deprecated namespaces in Chromium
>
> Bug: webrtc:42232595
> Change-Id: Iff6bc474d2bd5d40bf9652b5d36440c2c993e930
> No-Iwyu: No relevant changes
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/388081
> Auto-Submit: Evan Shrubsole <eshr@webrtc.org>
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#44445}

Bug: webrtc:42232595
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: Idbd838681ad822f2abf8039bf7c201a023aad392
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/388280
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Evan Shrubsole <eshr@webrtc.org>
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#44448}