(prejoin): fix mobile

react/features/base/devices/functions.js

 }
 
 /**
- * Returns true if there are devices of a specific type.
+ * Returns true if there are devices of a specific type or on native platform.
  *
  * @param {Object} state - The state of the application.
  * @param {string} type - The type of device: VideoOutput | audioOutput | audioInput.
  * @returns {boolean}
  */
 export function hasAvailableDevices(state: Object, type: string) {
+    if (state['features/base/devices'] === undefined) {
+        return true;
+    }
+
     return state['features/base/devices'].availableDevices[type].length > 0;
 }
 

react/features/device-selection/middleware.js

     if (action.type === UPDATE_DEVICE_LIST) {
         const state = store.getState();
         const { popupDialogData } = state['features/device-selection'];
-        const { availableDevices } = state['features/base/devices'];
+        const { availableDevices } = state['features/base/devices'] || {};
 
         if (popupDialogData) {
             popupDialogData.transport.sendEvent({