[iOS][cr/b] Move about_flags.* to flags/

Bug: 973040.
Change-Id: If94a974ab68c947144cd0df04f3a843fadd391d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1678477
Commit-Queue: Nazerke Kalidolda <[email protected]>
Commit-Queue: Gauthier Ambard <[email protected]>
Reviewed-by: Gauthier Ambard <[email protected]>
Reviewed-by: Mark Cogan <[email protected]>
Auto-Submit: Nazerke Kalidolda <[email protected]>
Cr-Commit-Position: refs/heads/master@{#672522}
7 files changed