fix: Adapt app lifecycle states. In Android would the permission pop up again af…

…ter denying in the first time.

@@ -162,16 +162,16 @@ class _MobileScannerState extends State<MobileScanner>
 
     switch (state) {
       case AppLifecycleState.resumed:
-        _resumeFromBackground = false;
-        _startScanner();
+        if (_resumeFromBackground) {
+          _startScanner();
+        }
         break;
       case AppLifecycleState.paused:
         _resumeFromBackground = true;
         break;
       case AppLifecycleState.inactive:
-        if (!_resumeFromBackground) {
-          _controller.stop();
-        }
+        _resumeFromBackground = true;
+        _controller.stop();
         break;
       case AppLifecycleState.detached:
         break;