feat: add autoStart parameter

@@ -64,6 +64,12 @@ class _MobileScannerState extends State<MobileScanner>
 
   /// Start the given [scanner].
   void _startScanner(MobileScannerController scanner) {
+    if (!_controller.autoStart) {
+      debugPrint(
+        'mobile_scanner: not starting automatically because autoStart is set to false in the controller.',
+      );
+      return;
+    }
     scanner.start().then((arguments) {
       // ignore: deprecated_member_use_from_same_package
       widget.onStart?.call(arguments);

@@ -19,6 +19,7 @@ class MobileScannerController {
     this.returnImage = false,
     @Deprecated('Instead, use the result of calling `start()` to determine if permissions were granted.')
         this.onPermissionSet,
+    this.autoStart = true,
   }) {
     // In case a new instance is created before calling dispose()
     if (controllerHashcode != null) {
@@ -64,6 +65,9 @@ class MobileScannerController {
   /// [DetectionSpeed.normal] (which is the default value).
   final int detectionTimeoutMs;
 
+  /// Automatically start the mobileScanner on initialization.
+  final bool autoStart;
+
   /// Sets the barcode stream
   final StreamController<BarcodeCapture> _barcodesController =
       StreamController.broadcast();