Dismiss the keyguard through #notifyKeyguardAuthentiated

In case a pending dismiss action exists when dreaming.

Update integration test

Test: manually launch an intent from dreaming and authenticate
through the alternate bouncer => see intent gets triggered
after authentication
Test: atest KeyguardViewMediatorTest
Fixes: 277284836

Change-Id: Ib67e2e0d9b7c1d59921c13d21e307c2292bd261b