Fix flicker of “touch to unlock anytime” toggle

Fixes flicker of toggle by setting not visible when launching confirm
pin/pattern/password or enrollment prior to displaying
FingerprintSettings. Also cleans up FingerprintSettings and
security_settings_fingerprint.xml to better separate SFPS and non-SFPS
logic and rename methods for clarity

Test: (manual) navigate to sfps fp settings and observe toggle doesn’t flicker
Test: make RunSettingsRoboTests ROBOTEST_FILTER=FingerprintSettingsRequireScreenOnToAuthPreferenceControllerTest
Test: make RunSettingsRoboTests ROBOTEST_FILTER=FingerprintSettingsUnlockCategoryControllerTest
Fixes: 263843645
Change-Id: Ide3a666fc31b926ac14645dc22d090f77d81f901