Don't blur during app launch animations

During app launch, we might poke a hole into the shade window to reveal
the app. We should not blur what's behind the shade, otherwise the app
window would also be blurred.

Also, even when dismissing the shade sliding it, the blur spring would
create an unpleasant feeling.

Test: manual
Test: atest NotificationShadeDepthControllerTest
Test: atest ActivityLaunchAnimatorTest
Test: atest KeyguardViewMediatorTest
Test: atest StatusBarNotificationActivityStarterTest
Fixes: 190086066
Change-Id: Ie5e5df7496eca74ca2715d2df8467636198c60f8