Revert "[power bookmarks] React to background changes in subscriptions"

This reverts commit f48885ec.

Reason for revert: Chrome Sheriff: Tree is closed.

Original change's description:
> [power bookmarks] React to background changes in subscriptions
>
> The subscription state can change while the bottomsheet is displayed.
> This could leave the bottomsheet out of date and potentially make bad
> requests.
>
> Bug: 1354230
> Change-Id: I1147d278cb807f9e2b520faabb00487086e2249b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3829038


> Reviewed-by: David Trainor <dtrainor@chromium.org>
> Reviewed-by: Matthew Jones <mdjones@chromium.org>
> Commit-Queue: Brandon Wylie <wylieb@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1041163}

Bug: 1354230
Change-Id: Ic47837b4271dbb7bcab0af8996b209d133143241
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3866671
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Iman Saboori <isaboori@google.com>
Commit-Queue: Iman Saboori <isaboori@google.com>
Cr-Commit-Position: refs/heads/main@{#1041175}