Removing borisv@chromium.org from the list of owners and adding

milagreen@chromium.org to the list of owners (chrome/updater).

Change-Id: I9a5b8be05ecca9011a2c37e1e8a406d94d7f07b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1800520
Auto-Submit: Mila Green <milagreen@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Commit-Queue: Joshua Pawlicki <waffles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#696073}

chrome/updater/OWNERS

-borisv@chromium.org
 ganesh@chromium.org
+milagreen@chromium.org
 sorin@chromium.org
 waffles@chromium.org