Updated Acceleration to firmware default

Updated Acceleration to firmware default to increase time estimation accuracy and match firmware default

resources/definitions/anycubic_i3_mega_s.def.json

@@ -44,7 +44,7 @@
 
         "material_diameter": { "default_value": 1.75 },
 
-        "acceleration_print": { "value": 1800 },
+        "acceleration_print": { "value": 1500 },
         "acceleration_travel": { "value": 3000 },
         "acceleration_travel_layer_0": { "value": "acceleration_travel" },
         "acceleration_roofing": { "enabled": "acceleration_enabled and roofing_layer_count > 0 and top_layers > 0" },

resources/definitions/anycubic_i3_mega_x.def.json

@@ -12,6 +12,9 @@
         "machine_name": { "default_value": "Anycubic i3 Mega X" },
         "machine_width": { "default_value": 300 },
         "machine_height": { "default_value": 305 },
-        "machine_depth": { "default_value": 300 }
+        "machine_depth": { "default_value": 300 },
+
+        "acceleration_print": { "value": 400 },
+        "acceleration_travel": { "value": 400 }
 	}
 }