Default divider interaction to true if transition doesn't succeed

* Currently we disable interactions at the beginning of a resize
transition and then re-enable on success
* When the fold/unfold happens, the transition to resize gets
clobbered/consumed by another transition, so the success callback for
re-enabling never runs
* Prior to ag/25604240 this was never an issue since we unconditionally
enabled divider interaction

Fixes: 318759451
Test: Repro steps don't leave divider uninteractable
Flag: None
Change-Id: I6af18c8175ea3ec7070bda03ebc8fb9c08f78c17