Move default album grid size to Constants

lib/core/configuration.dart

@@ -60,7 +60,6 @@ class Configuration {
   static const keyKey = "key";
   static const keyShouldBackupOverMobileData = "should_backup_over_mobile_data";
   static const keyAlbumGridSize = "album_grid_size";
-  static const defaultAlbumGridSize = 4;
   static const keyShouldBackupVideos = "should_backup_videos";
 
   // keyShouldKeepDeviceAwake is used to determine whether the device screen

lib/core/constants.dart

@@ -15,6 +15,7 @@ const int jan011981Time = 347155200000000;
 const int galleryLoadStartTime = -8000000000000000; // Wednesday, March 6, 1748
 const int galleryLoadEndTime = 9223372036854775807; // 2^63 -1
 const int batchSize = 1000;
+const defaultAlbumGridSize = 4;
 
 // used to identify which ente file are available in app cache
 // todo: 6Jun22: delete old media identifier after 3 months