feat: add icon to dropdown button in language view (#2031)

- drop down button gives the default icon
- set auto focus true in dropdown button
- add padding to dropdown button
- change edgeIsets.only(left,right) to edgeInsets.symmetric(horizontal)

frontend/appflowy_flutter/lib/workspace/presentation/settings/widgets/settings_language_view.dart

@@ -57,12 +57,14 @@ class _LanguageSelectorDropdownState extends State<LanguageSelectorDropdown> {
       onEnter: (event) => {hoverEnterLanguage()},
       onExit: (event) => {hoverExitLanguage()},
       child: Container(
-        margin: const EdgeInsets.only(left: 8, right: 8),
+        margin: const EdgeInsets.symmetric(horizontal: 8),
         decoration: BoxDecoration(
           borderRadius: BorderRadius.circular(8),
           color: currHoverColor,
         ),
         child: DropdownButtonHideUnderline(
+          child: Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 6),
             child: DropdownButton<Locale>(
               value: context.locale,
               onChanged: (val) {
@@ -72,12 +74,10 @@ class _LanguageSelectorDropdownState extends State<LanguageSelectorDropdown> {
                       .setLocale(context, val!);
                 });
               },
-            icon: const Visibility(
-              visible: false,
-              child: (Icon(Icons.arrow_downward)),
-            ),
+              autofocus: true,
               borderRadius: BorderRadius.circular(8),
-            items: EasyLocalization.of(context)!.supportedLocales.map((locale) {
+              items:
+                  EasyLocalization.of(context)!.supportedLocales.map((locale) {
                 return DropdownMenuItem<Locale>(
                   value: locale,
                   child: Padding(
@@ -89,6 +89,7 @@ class _LanguageSelectorDropdownState extends State<LanguageSelectorDropdown> {
             ),
           ),
         ),
+      ),
     );
   }
 }