Fixes for backups for Android. Fixes for send almost all amount.

lib/src/screens/backup/backup_page.dart

@@ -14,6 +14,7 @@ import 'package:cake_wallet/utils/show_pop_up.dart';
 import 'package:cake_wallet/view_model/backup_view_model.dart';
 import 'package:cake_wallet/core/execution_state.dart';
 import 'package:cake_wallet/src/screens/base_page.dart';
+import 'package:permission_handler/permission_handler.dart';
 
 class BackupPage extends BasePage {
   BackupPage(this.backupViewModelBase);
@@ -99,8 +100,6 @@ class BackupPage extends BasePage {
               actionRightButton: () async {
                 Navigator.of(dialogContext).pop();
                 final backup = await backupViewModelBase.exportBackup();
-                await backupViewModelBase.saveToDownload(
-                    backup.name, backup.content);
 
                 if (Platform.isAndroid) {
                   onExportAndroid(context, backup);
@@ -123,9 +122,16 @@ class BackupPage extends BasePage {
               rightButtonText: 'Save to Downloads',
               leftButtonText: 'Share',
               actionRightButton: () async {
-                Navigator.of(dialogContext).pop();
+                final permission = await Permission.storage.request();
+
+                if (permission.isDenied) {
+                  Navigator.of(dialogContext).pop();
+                  return;
+                }
+
                 await backupViewModelBase.saveToDownload(
                     backup.name, backup.content);
+                Navigator.of(dialogContext).pop();
               },
               actionLeftButton: () {
                 Navigator.of(dialogContext).pop();

lib/src/screens/exchange_trade/exchange_trade_page.dart

@@ -255,11 +255,11 @@ class ExchangeTradeState extends State<ExchangeTradeForm> {
                         .pendingTransaction.feeFormatted,
                     rightButtonText: S.of(context).ok,
                     leftButtonText: S.of(context).cancel,
-                    actionRightButton: () {
+                    actionRightButton: () async {
                       Navigator.of(context).pop();
-                      widget.exchangeTradeViewModel.sendViewModel
+                      await widget.exchangeTradeViewModel.sendViewModel
                           .commitTransaction();
-                      showPopUp<void>(
+                      await showPopUp<void>(
                           context: context,
                           builder: (BuildContext context) {
                             return Observer(builder: (_) {
@@ -359,10 +359,10 @@ class ExchangeTradeState extends State<ExchangeTradeForm> {
                           });
                     },
                     actionLeftButton: () => Navigator.of(context).pop(),
-                    feeFiatAmount: widget.exchangeTradeViewModel.sendViewModel
-                        .pendingTransaction.feeFormatted,
+                    feeFiatAmount: widget.exchangeTradeViewModel.sendViewModel.pendingTransactionFeeFiatAmount
+                        +  ' ' + widget.exchangeTradeViewModel.sendViewModel.fiat.title,
                     fiatAmountValue: widget.exchangeTradeViewModel.sendViewModel
-                            .pendingTransactionFeeFiatAmount +
+                            .pendingTransactionFiatAmount +
                         ' ' +
                         widget.exchangeTradeViewModel.sendViewModel.fiat.title,
                     recipientTitle: S.of(context).recipient_address,