Restore changes to IDS_XR_CONSENT_DIALOG_DESCRIPTION string

The above string has been changed when it was moved between files.
Because of this, it became an new untranslated string on translation
console.

Restoring it would bring back the translations, avoiding a
time-consuming translation cycle.

Bug: 971444
Change-Id: I64467c5c1d2d2a72ffae13c43f3317a48d8926f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1646643
Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Bill Orr <billorr@chromium.org>
Commit-Queue: Suman Kancherla <sumankancherla@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666496}