Fixed thread visibility issues in SignalClient. (#819)

Added @volatile to isConnected, currentWs, and isReconnecting fields
that are accessed from multiple threads (OkHttp callbacks and IO
dispatcher coroutines).

Author: adrian-niculescu

.changeset/fix-signal-client-volatile.md

@@ -0,0 +1,5 @@
+---
+"client-sdk-android": patch
+---
+
+Fix thread visibility issues in SignalClient that could cause messages to be silently dropped.

livekit-android-sdk/src/main/java/io/livekit/android/room/SignalClient.kt

@@ -79,9 +79,14 @@ constructor(
     private val ioDispatcher: CoroutineDispatcher,
     private val networkInfo: NetworkInfo,
 ) : WebSocketListener() {
+    @Volatile
     var isConnected = false
         private set
+
+    @Volatile
     private var currentWs: WebSocket? = null
+
+    @Volatile
     private var isReconnecting: Boolean = false
     var listener: Listener? = null
     internal var serverVersion: Semver? = null