doc updates

Author: Chris Yang

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile.dart

@@ -20,7 +20,7 @@ class Tile {
   /// A byte array containing the image data.
   final Uint8List data;
 
-  /// Converts this object to something serializable in JSON.
+  /// Converts this object to JSON.
   dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile_overlay.dart

@@ -121,7 +121,7 @@ class TileOverlay {
     );
   }
 
-  /// Converts this object to something serializable in JSON.
+  /// Converts this object to JSON.
   dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile_overlay_updates.dart

@@ -78,7 +78,7 @@ class TileOverlayUpdates {
 
   Set<TileOverlay> _tileOverlaysToChange;
 
-  /// Converts this object to something serializable in JSON.
+  /// Converts this object to JSON.
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> updateMap = <String, dynamic>{};