fix(android): derive current channel from snapshot

apps/chanora_flutter/lib/main.dart

@@ -995,6 +995,16 @@ class _BetaHomeState extends State<_BetaHome> {
 
   void _applySnapshot(rust.BridgeSnapshot snap) {
     _snapshot = snap;
+    for (final client in snap.clients) {
+      if (client.id == snap.ownClientId) {
+        _currentVoiceChannelId = client.channel;
+        _pendingVoiceChannelId = null;
+        _inChannel = true;
+        _canJoinVoiceChannel = true;
+        _canLeaveVoiceChannel = false;
+        return;
+      }
+    }
   }
 
   Future<void> _onShowDiagnostics(BuildContext context) async {