Revert "Fix a crash when registering/unregistering a smartspace timer listener."

This reverts commit e90606d9.

Reason for revert: seems to be the culprit for b/323782475
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:9ae796c523466f44d4204ba7ee70cc6b610b7a7c)
Merged-In: I7b864821fe1df20446a21a08e779ec0441e553a4
Change-Id: I7b864821fe1df20446a21a08e779ec0441e553a4