Decouple feature flag and predictions

- Always default to true for ENABLE_HYBRID_HOTSEAT
- Allow launcher to show predictions anytime regardless of notification and on-boarding.
- Remove past beta specific plans
- Migrate if first screen can accommodate hotseat items otherwise show tip

Bug: 142753423
Test: Manual
Change-Id: I142cd95d779964822da07a96e5884a0c82813742
(cherry picked from commit 49d0f64a)