Disable warning on blocking one-way call from autofill server.

This behavior existed since autofill was introduced on O and most likely
won't be fixed on Q, so there's no point on warning. In fact, the warning is
often a red herring for other issues, not to mention a big logcat spammer.

Bug: 35708678
Test: manual verification looking at logcat

Change-Id: I40be4ce25abc5b097ea67e5cb34bb9c4237f0826
(cherry picked from commit 385ee539)