fix(voip): reuse OkHttpClient and close response body in MediaCallsAnswerRequest

Address CodeRabbit resource leak warning: reuse the OkHttpClient singleton
instead of creating a new instance per request, and wrap the Response in
response.use {} to ensure the body is closed after use.

Author: diegolmello

android/app/src/main/java/chat/rocket/reactnative/voip/DDPClient.kt

@@ -21,10 +21,13 @@ class DDPClient {
 
     companion object {
         private const val TAG = "RocketChat.DDPClient"
+        private val sharedClient = OkHttpClient.Builder()
+            .pingInterval(30, TimeUnit.SECONDS)
+            .build()
     }
 
     private var webSocket: WebSocket? = null
-    private var client: OkHttpClient? = null
+    private val client: OkHttpClient = sharedClient
     private var sendCounter = 0
     private var isConnected = false
     private val mainHandler = Handler(Looper.getMainLooper())
@@ -40,14 +43,9 @@ class DDPClient {
 
         Log.d(TAG, "Connecting to $wsUrl")
 
-        val httpClient = OkHttpClient.Builder()
-            .pingInterval(30, TimeUnit.SECONDS)
-            .build()
-        client = httpClient
-
         val request = Request.Builder().url(wsUrl).build()
 
-        webSocket = httpClient.newWebSocket(request, object : WebSocketListener() {
+        webSocket = client.newWebSocket(request, object : WebSocketListener() {
             override fun onOpen(webSocket: WebSocket, response: Response) {
                 Log.d(TAG, "WebSocket opened")
                 val connectMsg = JSONObject().apply {
@@ -142,8 +140,6 @@ class DDPClient {
         onCollectionMessage = null
         webSocket?.close(1000, null)
         webSocket = null
-        client?.dispatcher?.executorService?.shutdown()
-        client = null
     }
 
     private fun nextMessage(msg: String): JSONObject {

android/app/src/main/java/chat/rocket/reactnative/voip/MediaCallsAnswerRequest.kt

@@ -36,6 +36,7 @@ class MediaCallsAnswerRequest(
     companion object {
         private const val TAG = "RocketChat.MediaCallsAnswerRequest"
         private val JSON_MEDIA_TYPE = "application/json; charset=utf-8".toMediaType()
+        private val httpClient = OkHttpClient()
 
         @JvmStatic
         fun fetch(
@@ -107,18 +108,19 @@ class MediaCallsAnswerRequest(
             .post(requestBody)
             .build()
 
-        val client = OkHttpClient()
-        client.newCall(request).enqueue(object : Callback {
+        httpClient.newCall(request).enqueue(object : Callback {
             override fun onFailure(call: Call, e: IOException) {
                 Log.e(TAG, "MediaCallsAnswerRequest failed for callId=$callId: ${e.message}")
                 onResult(false)
             }
 
             override fun onResponse(call: Call, response: okhttp3.Response) {
-                val code = response.code
-                val success = code in 200..299
-                Log.d(TAG, "MediaCallsAnswerRequest response for callId=$callId: code=$code success=$success")
-                onResult(success)
+                response.use {
+                    val code = it.code
+                    val success = code in 200..299
+                    Log.d(TAG, "MediaCallsAnswerRequest response for callId=$callId: code=$code success=$success")
+                    onResult(success)
+                }
             }
         })
     }