Added Google Drive storage location

lib/models/vehicle.dart

@@ -4,6 +4,7 @@ class Vehicle {
   final String model;
   final String color;
   final String licensePlate;
+  final DateTime updatedAt;
 
   Vehicle({
     required this.id,
@@ -11,6 +12,7 @@ class Vehicle {
     required this.model,
     required this.color,
     required this.licensePlate,
+    required this.updatedAt,
   });
 
   String get displayName => '$color $make $model ($licensePlate)';
@@ -20,6 +22,7 @@ class Vehicle {
     String? model,
     String? color,
     String? licensePlate,
+    DateTime? updatedAt,
   }) {
     return Vehicle(
       id: id,
@@ -27,6 +30,7 @@ class Vehicle {
       model: model ?? this.model,
       color: color ?? this.color,
       licensePlate: licensePlate ?? this.licensePlate,
+      updatedAt: updatedAt ?? this.updatedAt,
     );
   }
 
@@ -36,6 +40,7 @@ class Vehicle {
         'model': model,
         'color': color,
         'licensePlate': licensePlate,
+        'updatedAt': updatedAt.toIso8601String(),
       };
 
   factory Vehicle.fromJson(Map<String, dynamic> json) => Vehicle(
@@ -44,5 +49,8 @@ class Vehicle {
         model: json['model'] as String,
         color: json['color'] as String,
         licensePlate: json['licensePlate'] as String,
+        updatedAt: json['updatedAt'] != null
+            ? DateTime.parse(json['updatedAt'] as String)
+            : DateTime.fromMillisecondsSinceEpoch(0),
       );
 }