Update corner radius from side panel to page content based on UX feedback.

Bug: 1472983
Change-Id: I1d2096d0dd9316da77c8f033433731a736add22a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4789746


Reviewed-by: Keren Zhu <kerenzhu@chromium.org>
Reviewed-by: Darryl James <dljames@chromium.org>
Commit-Queue: Caroline Rising <corising@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1184828}