[Permission] Show permission rejected error in the Cast Harmony Dialog

CastDialogView now checks the `is_permission_rejected_` flag in the
CastDialogModel and shows an error message.

Skipping translation check because some string modification is trivial.

internal only: UI string approved in https://docs.google.com/document/d/1AUr5W5YXzVi1GBJlHbcgglpGAH2X56CpZSbRocmTqHQ/edit?tab=t.0#heading=h.v4ircowursej

Bug: 354232680
Skip-Translation-Screenshots-Check: True
Change-Id: Idb9cc14e6a73307329f67e8a0b3f052e1e3b73d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5775517
Commit-Queue: Muyao Xu <muyaoxu@google.com>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1341176}