Use a consistent method to get tab group color list

This CL will make getTabGroupColorIdList the consistent method for Tab
group color list. Use this method for tab group color picker and getting
next suggested color ID.

The detail of this CL:
1. Move the getTabGroupColorIdList from ColorPickerUtils to
TabGroupColorUtils.
2. When get the color count map to get the next suggested color id, use
the getTabGroupColorIdList to get the color list and init a
LinkedHashMap. Remove unused color id order check.

Bug: 383584871
Change-Id: I692cf9e3e271b1ca8db8f8b3e33a0b8a43ec9260
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6088345
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1395411}