[Tab Group Parity] Adjust the width split logic for the color picker

Use the container layout's own width when determining whether to split
the color picker rows on the group creation dialog.

Bug: 334824790, 41490324
Change-Id: I2561ca5c91e069cf5bba4db6676978b4b0a3646e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5454437
Reviewed-by: Sky Malice <skym@chromium.org>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Commit-Queue: Brandon Fong <bjfong@google.com>
Cr-Commit-Position: refs/heads/main@{#1288279}