Add screenreader logic to verified message of progress dialog

When progress dialog change to confirmation state without text changing,
screenreader will read verified.

Bug:413192337

Change-Id: I969aaec7c3475f6506448487932464257b8324f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6497441
Commit-Queue: Yiwen Qian <yiwenqian@google.com>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Reviewed-by: Siyu An <siyua@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1456452}