Revert "Bundz rename [1]: rename the browser implementation of the AI manager"

This reverts commit 9da71c87ef146e7d34615107221dace6875887e9.

Reason for revert: this CL break android compilation.

Original change's description:
> Bundz rename [1]: rename the browser implementation of the AI manager
>
> Bug: 341851444
> Change-Id: Ib98561e00c3316a3214b7c429cf2d5fc4089bf57
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5553216
> Reviewed-by: Erik Chen <erikchen@chromium.org>
> Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
> Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
> Commit-Queue: Mingyu Lei <leimy@chromium.org>
> Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
> Cr-Commit-Position: refs/heads/main@{#1306573}

Bug: 341851444
Change-Id: Ia2b8963dfee3f4241be449f956c9972cc369d3b0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5571347
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Sayed El-Abady <elabadysayed@google.com>
Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1306669}