Decouple notification views from NotificationEntry

Bug: 395857098
Flag: com.android.systemui.notification_bundle_ui
Test: post notifications, view three states, reply to conversation,
validate bubble button (flag on and off)
Test: SmartReplyControllerTest
Test: RemoteInputEntryAdapterTest
Test: RemoteInputViewTest
Test: NotificationContentViewTest

Change-Id: I3d7a725269b151cf7daa0d42d57a3ade74ccb9a9