Fix UDFPS enroll when help received on first step

Fixes an issue where the UDFPS enroll progress drawable would complete
if an error resulted in a help message being sent on the first
enrollment step. Instead, the progress bar will now remain empty in this
case.

Test: Manual

Bug: 201364678
Bug: 201602528
Change-Id: I7df617287e448be3c40443b2fe0f1359b6ab2b82