fix(android, lib): permissions and memory safety

android/src/main/AndroidManifest.xml

@@ -8,6 +8,10 @@
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     <!-- to work with Wi-fi Direct API -->
     <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
+    <!-- to save the received files -->
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <!-- to save the received files -->
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 
     <uses-feature
         android:name="android.hardware.wifi.direct"

lib/src/platforms/android/socket_service/file_sockets_manager.dart

@@ -176,7 +176,10 @@ class FileSocketsManager {
         filesRequest: filesRequest,
         socket: socket,
         listener: _filesListener,
-        onDestroy: _filesSockets.remove,
+        onDestroy: (id) {
+          socket.close();
+          _filesSockets.remove(id);
+        },
       );
       Logger.info('Created a socket for the files pack ${filesRequest.id}');
       return true;