Correct AutoPictureInPictureSurveys prompt_result argument

This CL corrects the AutoPictureInPictureSurveys prompt_result argument,
replacing "AllowedOnce" with "AllowOnce".

Bug: 485932914, b:561879357
Change-Id: I5c707dba3c28a177056b9c64de5a063631d3a0db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8413047
Auto-Submit: Benjamin Keen <bkeen@google.com>
Commit-Queue: Yiren Wang <yrw@chromium.org>
Reviewed-by: Yiren Wang <yrw@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1698296}
NOKEYCHECK=True
GitOrigin-RevId: 1fd376f1354520d278714ed1957809c59199464b