Add yhanada@ to exo watchlist.

Bug: None
Change-Id: Ic22a6ce6ccdc3278cdb83b82849e828284ca5502
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3379626
Auto-Submit: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Kazuki Takise <takise@chromium.org>
Commit-Queue: Kazuki Takise <takise@chromium.org>
Cr-Commit-Position: refs/heads/main@{#957896}

WATCHLISTS

@@ -2508,7 +2508,8 @@
     'eme': ['eme-reviews@chromium.org'],
     'enterprise_reporting_private': ['domfc+watch@chromium.org',
                                      'anthonyvd+watch@chormium.org'],
-    'exo': ['crostini-ui+exo@chromium.org'],
+    'exo': ['crostini-ui+exo@chromium.org',
+            'yhanada+watchexo@chromium.org'],
     'explore_sites': ['chili+watch@chromium.org',
                       'dewittj+watch@chromium.org',
                       'dimich+watch@chromium.org',