feat: refine native iOS chat experience

Sources/LiveKit/VoiceSession.swift

@@ -377,16 +377,21 @@ final class VoiceSession: ObservableObject {
         }
     }
 
-    func selectVoice(_ id: String) async {
-        settings.voiceID = id
-        guard isReady else { return }
+    @discardableResult
+    func selectVoice(_ id: String) async -> Bool {
+        let previous = settings.voiceID
+        guard isReady else { settings.voiceID = id; return true }
         let generation = sessionGeneration
         do {
             try await controlChannel.setVoice(id, room: room)
-            guard generation == sessionGeneration else { return }
+            guard generation == sessionGeneration else { return false }
+            settings.voiceID = id
             logger.log("set_voice sent: \(id, privacy: .public)")
+            return true
         } catch {
+            settings.voiceID = previous
             logger.error("set_voice failed: \(String(describing: error), privacy: .public)")
+            return false
         }
     }