fix: fix speaker switching behavior for android. (#604)

Author: cloudwebrtc

example/lib/widgets/controls.dart

@@ -312,7 +312,7 @@ class _ControlsWidgetState extends State<ControlsWidget> {
             else
               PopupMenuButton<MediaDevice>(
                 icon: const Icon(Icons.settings_voice),
-                offset: Offset(0, -90),
+                offset: const Offset(0, -90),
                 itemBuilder: (BuildContext context) {
                   return [
                     PopupMenuItem<MediaDevice>(
@@ -355,7 +355,7 @@ class _ControlsWidgetState extends State<ControlsWidget> {
               icon: const Icon(Icons.mic_off),
               tooltip: 'un-mute audio',
             ),
-          if (!lkPlatformIs(PlatformType.iOS))
+          if (!lkPlatformIsMobile())
             PopupMenuButton<MediaDevice>(
               icon: const Icon(Icons.volume_up),
               itemBuilder: (BuildContext context) {
@@ -393,7 +393,7 @@ class _ControlsWidgetState extends State<ControlsWidget> {
                 ];
               },
             ),
-          if (!kIsWeb && lkPlatformIs(PlatformType.iOS))
+          if (!kIsWeb && lkPlatformIsMobile())
             IconButton(
               disabledColor: Colors.grey,
               onPressed: Hardware.instance.canSwitchSpeakerphone