WebUI cr-textarea: Default to CR2023 styles

Bug: 326116364
Change-Id: I3fbe99d3c569a74d93fd5c8471d60d2a1e3d29ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5425383


Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Teresa Mao <temao@chromium.org>
Reviewed-by: John Lee <johntlee@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1283471}