hugepage_text: Update OWNERS

- Remove shenhan and yunlian (they're no longer on the team that
  maintains this, and there are now people on the team with sufficient
  context)
- Add gbiv and manoj (two of said people ;) )

Bug: None
Change-Id: I6dc1f65b9a0ab84818175a01396ed83a78a732f9
Reviewed-on: https://chromium-review.googlesource.com/c/1372273Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: George Burgess <gbiv@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615627}

chromeos/hugepage_text/OWNERS

-yunlian@chromium.org
 llozano@chromium.org
-shenhan@chromium.org
 cmtice@chromium.org
+gbiv@chromium.org
+manojgupta@chromium.org