Refactor flags of Power Anomaly Tips in Settings Intelligence.(1/2)

- Remove unused flag is_battery_tips_feedback_enabled
- Update logic about is_battery_tips_enabled

Bug: 284893240
Test: Manual
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:24e269dd0a63b5cb98fec791708cfe294b5aa47c)
Change-Id: I826f517aa61e0c970048164706c4512ac3e0472d