Add capture skip active notification allowlist to message

In the "Your screen may be captured" notification message we need to
branch based on whether the "Your screen is captured" notification
will be shown. The user will explicitly be warned whether there will
be a future notification on active capture (see UX concept).

UX concept: go/screencapture-notification-allowlist-ux

DD: go/screencapture-notification-allowlist
Bug: 424104840
Change-Id: I80651f2398b002e8e48218bdc2086a7094b64653
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6651057
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Dominik Bylica <bylica@google.com>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Auto-Submit: Simon Hangl <simonha@google.com>
Cr-Commit-Position: refs/heads/main@{#1475549}