Fix typo in WATCHLISTS android-infra regex

Change-Id: I46a33d40a6f5ea96b905268a548e1c0c09c01f2c
Reviewed-on: https://chromium-review.googlesource.com/809024Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521692}

WATCHLISTS

@@ -43,7 +43,7 @@
     },
     'android_infra': {
       'filepath': 'build/config/android/' \
-                  'build/android/' \
+                  '|build/android/' \
                   '|testing/android/' \
                   '|tools/android/'
     },