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This moves the "downloading" and "error" states for contacts download on
the contact visibility dialog to be siblings with the zero state to
match the visual hierarchy in the spec and updates their strings.

Spec:
  https://docs.google.com/document/d/1s-KjC1mM4ZPYeYAO7oI8lXltS_1FaYYfMMnNDdbfRag

Screenshots:
  https://screenshot.googleplex.com/3eFV48bA2vLoMYW.png
  https://screenshot.googleplex.com/7fGRnhpS5zECRuU.png

Bug: b:168841167
Change-Id: I669866edd3c114bf34d5c1c77ddf89d02e1e909a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2519364
Commit-Queue: Michael Hansen <hansenmichael@google.com>
Reviewed-by: James Vecore <vecore@google.com>
Cr-Commit-Position: refs/heads/master@{#825125}