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

This is a reland of commit f48885ec

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 This could leave the bottomsheet out of date and potentially make bad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: Idb3030270789e93de066c814a2f0c7889a4b7e55
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3866712


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@{#1041706}