sunfish: Don't show search or more actions buttons when offline.

After selecting a region in screen capture while offline, don't show the
search or more actions buttons (i.e. only show the copy text button).

Followup will show an error in place of the buttons.

Bug: b:391713973
Change-Id: I12fc5379c3eab92a603d26e0aca048c22619fc03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6232661
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Elijah Hewer <hewer@chromium.org>
Commit-Queue: Michelle Chen <michellegc@google.com>
Cr-Commit-Position: refs/heads/main@{#1416512}