Fix OnCancelListener for Dialogs on swipe to dismiss.

Swipe to dismiss on dialogs did not dispatch onCancel events
to OnCancelListeners. Resolve by adding listener to monitor
swipe to dismiss events and dispatch onCancel events when
that occurs.

Bug: 33663411
Change-Id: I64ff29e008d485a4559eb3d1ff7f0e74dccff404
3 files changed