scan_manager_refactor rebranding

Dues to workflow changes and to various un-investigable issues, we need
to re-create a fresh flag for this

Bug: 396082772
Bug: 399940933
Bug: 313335632
Test: m .
Flag: com.android.bluetooth.flags.scan_manager_refactor
Flag: com.android.bluetooth.flags.only_start_scan_during_ble_on
Change-Id: I6a4777ac22c408aeb113ddea9233cf45ea4bea41