imp: fix flutter v3 warnings

@@ -46,7 +46,12 @@ android {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:18.0.0'
+
+    // Use this dependency to bundle the model with your app
+    implementation 'com.google.mlkit:barcode-scanning:17.0.2'
+    // Use this dependency to use the dynamically downloaded model in Google Play Services
+//    implementation 'com.google.android.gms:play-services-mlkit-barcode-scanning:18.0.0'
+
     implementation "androidx.camera:camera-camera2:1.2.0-alpha01"
     implementation 'androidx.camera:camera-lifecycle:1.2.0-alpha01'
 

@@ -47,7 +47,7 @@ class _MobileScannerState extends State<MobileScanner>
   @override
   void initState() {
     super.initState();
-    WidgetsBinding.instance?.addObserver(this);
+    WidgetsBinding.instance.addObserver(this);
     controller = widget.controller ?? MobileScannerController();
   }
 
@@ -131,7 +131,7 @@ class _MobileScannerState extends State<MobileScanner>
   @override
   void dispose() {
     controller.dispose();
-    WidgetsBinding.instance?.removeObserver(this);
+    WidgetsBinding.instance.removeObserver(this);
     super.dispose();
   }
 }