BootMaintenanceManagerUiLib depend on the LeagcyBootMaintUiLib to show the legacy menus. So we need to do the actions related to LegacyUi in BMM after the LeagcyBootMaintUiLib have been initialized. So now : 1). update menus (including legacy menus), 2) re-scan boot options (including legacy boot option) when opening the BMM form. We think when opening BMM form, the LeagcyBootMaintUiLib must have been initialized. Cc: Liming Gao <liming.gao@intel.com> Cc: Eric Dong <eric.dong@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Dandan Bi <dandan.bi@intel.com> Reviewed-by: Eric Dong <eric.dong@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>