[WE] Show first-time connection notification for pointing sticks

* The strings used in the notification are temporary and will be
  updated in a follow-up CL.

Bug: b/329686601
Change-Id: I379324f7510b8d53c80493532bd063778da10d4b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5513707
Reviewed-by: Muhammad Hasan Khan <mhasank@chromium.org>
Commit-Queue: Michael Checo <michaelcheco@google.com>
Reviewed-by: David Padlipsky <dpad@google.com>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1297268}