[flexiglass] Spread inputs when passing them to rememberSession

Fixes bug where empty inputs were causing the init block passed into rememberSession to be called when it shouldn't have been

Bug: 349868598
Test: manually verified that init block is no longer called in this situation
Flag: com.android.systemui.scene_container
Change-Id: I1add7034f0c68a6709439e3a8ca0f872b4fd5a33