Update ja.rs and Add "About Rustdesk" (#8784)

* Update ja.rs

Signed-off-by: creeper-0910 <56744841+creeper-0910@users.noreply.github.com>

* Update ja.rs

Signed-off-by: creeper-0910 <56744841+creeper-0910@users.noreply.github.com>

* Add 'About RustDesk'

Signed-off-by: creeper-0910 <56744841+creeper-0910@users.noreply.github.com>

---------

Signed-off-by: creeper-0910 <56744841+creeper-0910@users.noreply.github.com>

flutter/lib/desktop/pages/desktop_setting_page.dart

@@ -1806,7 +1806,7 @@ class _AboutState extends State<_About> {
           child: SingleChildScrollView(
             controller: scrollController,
             physics: DraggableNeverScrollableScrollPhysics(),
-            child: _Card(title: '${translate('About')} RustDesk', children: [
+            child: _Card(title: translate('About RustDesk'), children: [
               Column(
                 crossAxisAlignment: CrossAxisAlignment.start,
                 children: [

flutter/lib/mobile/pages/connection_page.dart

@@ -395,7 +395,7 @@ class _WebMenuState extends State<WebMenu> {
               [
                 PopupMenuItem(
                   value: "about",
-                  child: Text('${translate('About')} RustDesk'),
+                  child: Text(translate('About RustDesk')),
                 )
               ];
         },

flutter/lib/mobile/pages/settings_page.dart

@@ -807,7 +807,7 @@ void showThemeSettings(OverlayDialogManager dialogManager) async {
 void showAbout(OverlayDialogManager dialogManager) {
   dialogManager.show((setState, close, context) {
     return CustomAlertDialog(
-      title: Text('${translate('About')} RustDesk'),
+      title: Text(translate('About RustDesk')),
       content: Wrap(direction: Axis.vertical, spacing: 12, children: [
         Text('Version: $version'),
         InkWell(