oak birch: revamp birch bar view

This cl adds a new API to BirchBarView to set up multiple chips and
clear existing chips. This API is for initializing and updating the
bar contents.

Bug: b:331482520
Change-Id: I13cd892040c3c963e313682f7f06756b4e0e7c69
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5399050


Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Xiaodan Zhu <zxdan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1279209}