[CrOS MultiDevice] Tweak string in multi-device setup flow.

Before this CL the UI looked like this:

  When you connect your devices you agree that your Chromebook can:
    * Install apps on your Chromebook
    * ...

This sounds a bit awkward, since "your Chromebook" is repeated twice.
This CL changes the first bullet point to "Automatically install apps"
instead.

Bug: 950691
Change-Id: Ibbe2a203f7a2a921541c09eabe393c7b0ad1f615
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1650121
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Jeremy Klein <jlklein@chromium.org>
Auto-Submit: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Jeremy Klein <jlklein@chromium.org>
Cr-Commit-Position: refs/heads/master@{#667224}