[ios] Fixed password generation action sheet styles

Added attributed strings handling to action sheet coordinator.

Bug: 953625, 953624
Change-Id: Ic70b68fb8e124c12696a971fafe9d6db47dce65e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1569938
Reviewed-by: Mark Cogan <marq@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653520}
4 files changed