Don't show KeyguardPresentation on the display which is always unlocked

It's already the case that always unlocked display are in their own
group, so with the existing logic we wont' show KeyguardPresentation on
them. It's displays that are NOT always unlocked but also in a
non-default group that we're changing to show KeyguardPresentation on.

Bug: 218587709
Test: atest KeyguardDisplayManagerTest
Change-Id: Idf1f71b59941daeb30f1bef3d87717e01e8d8f0f