Add null-check for lockscreenSmartspace

There's no guarantee in unlockToLauncherWithInWindowAnimations,
that lockscreenSmartspace isn't null. Let's protect against this.

Fixes: 234858774
Test: atest KeyguardUnlockAnimationControllerTest
Change-Id: Ib9f973d189e3935b019f5295ca0a87a56a09b27c