Add OWNERS file for user_education_strings_grdp

Spotted when looking for reviewers for a small string change CL that there are currently only top-level components owners for the translation screenshot updates.

Adding OWNERS to match the definition for the corresponding .grd file.

Change-Id: I37308cf58caa659e583a1198432c8be74ef748c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6020723
Commit-Queue: James Lee <ljjlee@google.com>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Auto-Submit: James Lee <ljjlee@google.com>
Commit-Queue: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1383576}