Add watchlist for Lens desktop

Adding a WATCHLIST so our team gets notified of any changes in the
Lens codebase.

Change-Id: I11caec2e97f0d2c2c226600ab3941c3edbabfbc0
Fixed: 392630443
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6203261
Commit-Queue: Duncan Mercer <mercerd@google.com>
Reviewed-by: Ali Stanfield <stanfield@google.com>
Cr-Commit-Position: refs/heads/main@{#1411861}

WATCHLISTS

@@ -1441,6 +1441,10 @@
                   'ios/chrome/browser/language|'\
                   'ios/web_view/internal/language'
     },
+    'lens_desktop': {
+      'filepath': 'components/lens/|'\
+                  'chrome/browser/ui/lens/'
+    },
     'libaom': {
       'filepath': 'third_party/libaom/',
     },
@@ -2989,6 +2993,9 @@
                                             'simonha@google.com'],
     'kiosk': ['chromeos-kiosk-eng+watch@google.com'],
     'language': ['language-reviews@chromium.org'],
+    'lens_desktop': ['lens-chrome-eng+reviews@google.com',
+                     'stanfield+watch@google.com',
+                     'mercerd+watch@google.com'],
     'libaom': ['fgalligan@chromium.org',
                'jianj@chromium.org',
                'jzern@chromium.org',