Updated fieldtrial entry for Desktop Partial Translate.

Also, bumping min AGSA version for the Assistant study.

Change-Id: Ic66c1acc59043024dbb6c9e93ff1091bd4d1c7fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4061021


Commit-Queue: Basia Zimirska <basiaz@google.com>
Reviewed-by: Anthony Cui <cuianthony@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1076562}