Let HelperManager throw underlying exceptions when failing to find impl.

Submitting this in internal first to coordinate with changes to dialog
dismissal util.

Sample output for new error messaging:
https://paste.googleplex.com/4571972094656512

Bug:130251361
Test: Manual
Change-Id: I42c9e761aaa21206623547d480d1fefe091db6c8
Merged-In: I42c9e761aaa21206623547d480d1fefe091db6c8
(cherry picked from commit 5ebfc24cb7a030dc04372735cbc0bc43ef7a4ac7)