[flexiglass] Propagate onKeyguard to child rows

Fixes: 391230625
Test: manual
 1. Receive a notification group whilst on AOD
 2. Unlock, open shade
 3. Observe: all notifications in group are expandable
Flag: com.android.systemui.scene_container
Change-Id: I1d1d20e41e6607e09046925eb2365c596ff35aed