[Benefits] Add IPH for educating users on the existence of credit card benefits.

Screenshot: https://screenshot.googleplex.com/8S7ys5wrcGMk6Yq.png
Mock: https://screenshot.googleplex.com/dhqyBGVzd9ALY3M.png
Fixed: b/323441257
Change-Id: I393d4dd94e5086ca8779c0107ea89d852575eae2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5379163


Reviewed-by: Olivia Saul <jsaul@google.com>
Commit-Queue: Justin Wells <justinleewells@google.com>
Reviewed-by: Alexander Tekle <alexandertekle@google.com>
Reviewed-by: Dana Fried <dfried@chromium.org>
Reviewed-by: Jan Keitel <jkeitel@google.com>
Cr-Commit-Position: refs/heads/main@{#1282156}