Add a bouncer string for adaptive auth

Flag: ACONFIG android.adaptiveauth.enable_adaptive_auth DEVELOPMENT
Bug: 285053096
Test: 1. Trigger 5 failed biometric attempts and/or primary auth
         attempts from BiometricPrompt or Settings (not on Keyguard),
         which will lock the device out
      2. See bouncer message
Test: atest KeyguardViewMediatorTest
Change-Id: Ie6140a866bd77020734f7c868d0b2a470a904683