[JellyBean] Debug shortcut for dynamic color

Added a debug shortcut that toggles between two dynamic colors.

TEST=Ran locally with both Jelly on and off. The debug shortcut does toggle colors throughout ChromeOS.
BUG=b/245617317

Change-Id: I237d7fdd910bb41d06df3e1894ab1ede04e66299
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3880890


Reviewed-by: Sean Kau <skau@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Jeffrey Young <cowmoo@chromium.org>
Commit-Queue: Erica Lee <ericamlee@google.com>
Cr-Commit-Position: refs/heads/main@{#1045458}