[Bouncer] Apply interpolation to udfps

Apply interpolation to udfps view controller when boucer is in transit.
Also rename the function so that it implies that it affects all elements
that need to hide in order to show the bouncer.

Bug: 228282858
Test: Manual
Change-Id: I27d192fb2576c8e02ac193eaee2836da4027c88f
11 files changed