Fixes a typo in DEPS.

R=oshima@chromium.org
TEST=None
BUG=None
NOTRY=true

Review URL: https://codereview.chromium.org/314793002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274617 0039d316-1c4b-4281-b951-d872f2087c98

athena/activity/public/DEPS

 include_rules = [
-  "-athena/task",
+  "-athena/activity",
   "+athena/athena_export.h",
 ]