Ensure smooth dismiss

When flinging and not releasing your finger, notifications
may flicker due to the shade expansion being reset to 1.

Ignore those values.

Fixes: 333710738
Test: atest KeyguardInteractorTest
Flag: ACONFIG com.android.systemui.migrate_clocks_to_blueprint
TEAMFOOD

Change-Id: If3aeb9afd404fffbf280855877680686d6a0d20c