Fix issues with SUW on fingerprint devices

Fixes the following issues related to fingerprint/face in Setup Wizard:
- Ensures super.onStop() is called by all enrollment-related Activities

Test: Proceed through Setup Wizard on factory reset Pixel 3 XL
Before: Periodic crash dialogs and stuck on fingerprint enrollment
After: Able to proceed through wizard and enroll fingerprint normally

Bug: 147325159
Change-Id: I76eb8c944140aa68f78eaea3702f440102b779c6