🐛 Fix LCD contrast/brightness init (#23567)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Marlin/src/inc/Conditionals_post.h

   #define _LCD_CONTRAST_MIN  255
   #define _LCD_CONTRAST_INIT 255
 #elif ENABLED(FYSETC_MINI_12864)
+  #define _LCD_CONTRAST_MIN  180
   #define _LCD_CONTRAST_INIT 220
 #elif ENABLED(ULTI_CONTROLLER)
   #define _LCD_CONTRAST_INIT 127

Marlin/src/lcd/marlinui.cpp

 #endif
 
 #if HAS_LCD_CONTRAST
-  uint8_t MarlinUI::contrast; // Initialized by settings.load()
-
+  uint8_t MarlinUI::contrast = LCD_CONTRAST_DEFAULT; // Initialized by settings.load()
   void MarlinUI::set_contrast(const uint8_t value) {
     contrast = constrain(value, LCD_CONTRAST_MIN, LCD_CONTRAST_MAX);
     _set_contrast();

Marlin/src/module/settings.cpp

     update_software_endstops((AxisEnum)i);
   }
 
+  TERN_(HAS_LCD_CONTRAST, ui.refresh_contrast());
+  TERN_(HAS_LCD_BRIGHTNESS, ui.refresh_brightness());
+
   TERN_(ENABLE_LEVELING_FADE_HEIGHT, set_z_fade_height(new_z_fade_height, false)); // false = no report
 
   TERN_(AUTO_BED_LEVELING_BILINEAR, refresh_bed_level());
       // LCD Contrast
       //
       {
-        _FIELD_TEST(lcd_contrast);
         uint8_t lcd_contrast;
+        _FIELD_TEST(lcd_contrast);
         EEPROM_READ(lcd_contrast);
-        TERN_(HAS_LCD_CONTRAST, if (!validating) ui.set_contrast(lcd_contrast));
+        TERN_(HAS_LCD_CONTRAST, if (!validating) ui.contrast = lcd_contrast);
       }
 
       //
       //
       {
         uint8_t lcd_brightness;
+        _FIELD_TEST(lcd_brightness);
         EEPROM_READ(lcd_brightness);
-        TERN_(HAS_LCD_BRIGHTNESS, if (!validating) ui.set_brightness(lcd_brightness));
+        TERN_(HAS_LCD_BRIGHTNESS, if (!validating) ui.brightness = lcd_brightness);
       }
 
       //
   //
   // LCD Contrast
   //
-  TERN_(HAS_LCD_CONTRAST, ui.set_contrast(DEFAULT_LCD_CONTRAST));
+  TERN_(HAS_LCD_CONTRAST, ui.contrast = LCD_CONTRAST_DEFAULT);
 
   //
   // LCD Brightness
   //
-  TERN_(HAS_LCD_BRIGHTNESS, ui.set_brightness(DEFAULT_LCD_BRIGHTNESS));
+  TERN_(HAS_LCD_BRIGHTNESS, ui.brightness = DEFAULT_LCD_BRIGHTNESS);
 
   //
   // Controller Fan