13450 merge 12267_new_flow and update to new flutter version

android/app/src/main/java/com/dinect/checker/MainActivity.java

@@ -38,6 +38,7 @@ public class MainActivity extends FlutterActivity {
 
     private MethodChannel mChannel;
     private Map mScannerArgs;
+    private Result scannerResult;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -59,6 +60,7 @@ public class MainActivity extends FlutterActivity {
                 result.success(BuildConfig.currency);
                 break;
             case "startScanner":
+                scannerResult = result;
                 startScannerActivity(call);
                 break;
             case "isOnline":
@@ -169,7 +171,7 @@ public class MainActivity extends FlutterActivity {
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         if (requestCode == START_SCANNER_REQUEST_CODE) {
             if (resultCode == RESULT_CANCELED) {
-                finish();
+              scannerResult.error("Scanning is cancelled", null, null);
             } else if (resultCode == RESULT_OK) {
                 if (data != null && data.getExtras() != null) {
                     String user = data.getExtras().getString("user", null);
@@ -178,7 +180,9 @@ public class MainActivity extends FlutterActivity {
                         ArrayList<String> args = new ArrayList<>(2);
                         args.add(user);
                         args.add(card);
-                        mChannel.invokeMethod("purchase", args);
+                        if(scannerResult != null) {
+                            scannerResult.success(args);
+                        }
                     } else {
                         String menuItem = data.getExtras().getString("item", null);
                         if (menuItem != null) {