Add nator@ to background_sync watchlist.

Change-Id: Idfb261ee92614c3c746066e2ed0c310a2a151fb9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1675352Reviewed-by: Rayan Kanso <rayankans@chromium.org>
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672020}

WATCHLISTS

@@ -1972,8 +1972,9 @@
     'autofill_payments': ['jsaul+autofillwatch@google.com'],
     'background_fetch': ['peter@chromium.org',
                          'rayankans+watch@chromium.org',
-                         'nator@chromium.org'],
+                         'nator+watch@chromium.org'],
     'background_sync': ['iclelland+watch@chromium.org',
+                        'nator+watch@chromium.org',
                         'peter@chromium.org',
                         'rayankans+watch@chromium.org'],
     'banners': ['dominickn+watch-banners@chromium.org',