Fix scrolling inside Read Aloud bottom sheets

The Read Aloud menu bottom sheet (and player sheet if the window is
small enough to require scrolling the player) needs to report its scroll
position to bottom sheet gesture handling code so that scrolling up in
the content won't close the sheet.

Bug: b/345465363
Change-Id: I30df92145a3e425819009590ffe98b62ff66832f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5615657


Commit-Queue: Andrea Gomez <andreaxg@google.com>
Commit-Queue: Ian Wells <iwells@chromium.org>
Reviewed-by: Andrea Gomez <andreaxg@google.com>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Auto-Submit: Ian Wells <iwells@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1312958}