Fix positive button when the click listener is not null.

Fixes changes made in ag/20171885:
https://screenshot.googleplex.com/4WeHHjy75A96wgf
https://screenshot.googleplex.com/3oQcLiY6AgYurB9

Bug: 252967902
Test: manual
Change-Id: I07985d540347c7b56982a90d386a5f93721344ea
1 file changed