[Flexiglass] Fix NotificationScrimNestedScrollConnection rememeberSession keys

We were passing in keys to rememberSession that were references to objects using remember, and thus the equality check was breaking once those references changed upon recomposition.

Bug: 403285138
Test: verified through logging that the relevant rememberSession equality checks now pass
Flag: com.android.systemui.scene_container
Change-Id: I846a4357b9359d02288cd707f5c2ebae5fbf0e36