[feature_notification_guide] Read params from finch

Bug: 1277400
Change-Id: I50410a0d06242343ce8a203a933d208e8e13f136
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3336417


Reviewed-by: Min Qin <qinmin@chromium.org>
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#959309}