🐛 Fix kinetic ABL mesh after refactor (#24107)

Followup to #23868

Marlin/src/feature/bedlevel/abl/bbl.h

 #include "../../../inc/MarlinConfigPre.h"
 
 class LevelingBilinear {
+private:
   static xy_pos_t grid_spacing, grid_start;
   static xy_float_t grid_factor;
   static bed_mesh_t z_values;

Marlin/src/gcode/bedlevel/abl/G29.cpp

         // Can't re-enable (on error) until the new grid is written
         abl.reenable = false;
       }
+
+      // Pre-populate local Z values from the stored mesh
+      TERN_(IS_KINEMATIC, COPY(abl.z_values, Z_VALUES_ARR));
+
     #endif // AUTO_BED_LEVELING_BILINEAR
 
   } // !g29_in_progress

Marlin/src/lcd/extui/dgus_reloaded/DGUSScreenHandler.cpp

   data.initialized = true;
   data.volume = dgus_display.GetVolume();
   data.brightness = dgus_display.GetBrightness();
-  data.abl = (ExtUI::getLevelingActive() && ExtUI::getMeshValid());
+  data.abl_okay = (ExtUI::getLevelingActive() && ExtUI::getMeshValid());
 
   memcpy(buff, &data, sizeof(data));
 }
   dgus_display.SetBrightness(data.initialized ? data.brightness : DGUS_DEFAULT_BRIGHTNESS);
 
   if (data.initialized) {
-    leveling_active = (data.abl && ExtUI::getMeshValid());
-
+    leveling_active = (data.abl_okay && ExtUI::getMeshValid());
     ExtUI::setLevelingActive(leveling_active);
   }
 }

Marlin/src/lcd/extui/dgus_reloaded/DGUSScreenHandler.h

     bool initialized;
     uint8_t volume;
     uint8_t brightness;
-    bool abl;
+    bool abl_okay;
   } eeprom_data_t;
 };