[NTP Theme] Add Chrome Colors bottom sheet

This CL introduces the Chrome Colors bottom sheet, featuring a
RecyclerView designed with these key requirements:

1. Dynamic Width: The color grid's width precisely matches the switch
above it, up to a maximum of 504dp.

2. Adaptive Columns: The grid displays the maximum fit columns,
automatically adjusting on device rotation.

3. Horizontal Centering: The entire color palette block (max 504dp
width) remains perfectly centered horizontally, regardless of column
count.

4. Consistent Spacing: A uniform 24dp gap is maintained between all
color palette (horizontal/vertical). The first and last columns have a
12dp margin relative to the switch's width or the 504dp maximum.

Technical & Spacing Details:

The grid's maximum width is capped at 504dp. This value is derived from
the space needed to display a full row of 7 items, based on the
component dimensions:

(7 items × 48dp) + (6 gaps × 24dp) + (2 outer margins × 12dp) = 504dp

The spacing model creates a uniform 24dp gap between all color palettes,
with a 12dp margin on the outside edges of the grid.

The change of the UI is shown in the following doc:
https://docs.google.com/document/d/1bMRVyyqOd0-cAmyTbL9IhKNU9uSvDdpdCngSzSXIHnk/edit?tab=t.0#bookmark=id.gse8zunxqjiy

Based on the log, the customized RecyclerView's `onMeasure` method is
called once when the bottom sheet is initially opened, and it's not
called during scrolling. When the device orientation changes,
`onMeasure` is called exactly five times. However, by using
mLastRecyclerViewWidth, the maxSpanCount is calculated just once after
the orientation change, and scrolling does not trigger subsequent
`onMeasure` calls. Here are the logs demonstrating this.
https://drive.google.com/file/d/1D5OAkhjH5hJ2GvXvDUQXK7MCmvOCGdGe/view?usp=sharing&resourcekey=0-tv_Rhdy_T6ZkHkcfFFbtkw

Skip-Translation-Screenshots-Check: True
Bug: 421436204
Change-Id: I9e206282517c94ae394e9a7e063fd03f3143b0dc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6793165
Commit-Queue: Yanling Hu <yanlinghu@google.com>
Reviewed-by: Xi Han <hanxi@chromium.org>
Reviewed-by: Xinyi Ji <xinyiji@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1501027}