Align assets and colors for biometric enroll intros

Replaces the existing MP4 shown on the face enroll intro/consent screen
with an updated lock asset that matches the current SUW theme. Also
updates the colors of assets and text on these screens for face and
fingerprint so that the two match.

Test: Manually tested both enrollments for dark and light system themes

Bug: 187681255
Change-Id: I119da913cfc76e02160f2efc4654cecf33f1f049