Convert notification redaction to tri-state

In service of adding a version of the public notification for OTP codes,
the NotificationLockscreenUserManager#needsRedaction method needs to be
updated to reflect the additional option for the public view (which is
not yet implemented).

Bug: 358403414
Test: atest NotificationLockscreenUserManagerTest
Flag: android.app.redact_sensitive_content_notifications_on_lockscreen
Change-Id: I9c2ff9bf04361f9d2b67ebc94fa7b66939c1183b