[flexiglass] HACKY: fix animations in NSSL

Removing NPVC removed the enable/disable of animations inside NSSL.  We can probably solve this with the NSV binder, but for now they are just always enabled (when flexiglass is).

Bug: 332732878
Test: expanding or dismissing notifications now animates the stack
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT
Change-Id: I6372d76b98dffa635949e0ab3a0f56fec9e5afce