For devices with udfps, always show bg on udfps

Also show background on lock icon and unlock
icons if the device supports udfps. This is to help
indicate the affordance is tappable.

Test: manually test with and w/o udfps
  - AOD <=> Lock screen
  - gpay wallet affordance on LS that requests udfps
  - slowly swipe up to show bouncer => udfps fades
  - slowly swipe down to expand notification shade => udfps fades
  - tap notification on ls, no bg animation
  - tap notification on locked shade, there is a bg animation
  - toggle on/off dark mode from lock screen
Fixes: 192403524
Change-Id: I5a19d3cd45c51af78a49d46126fc0678a3df6d6c