[CrOS PhoneHub] Fix localized string summary

The previous summary mistakenly said that this string was the title of a
dialog, which it was not (it was the text body). This confused
translators (see b/1209099), so I'm fixing it here.

Bug: 1106937
Change-Id: I6a4f25ce5e09223e38476dcbebaa3fa973a86c77
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2583108


Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Jimmy Gong <jimmyxgong@chromium.org>
Auto-Submit: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Jimmy Gong <jimmyxgong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835487}