feat(prejoin): Show warning if audio device does not receive data

lang/main.json

     "poweredby": "powered by",
     "prejoin": {
         "audioAndVideoError": "Audio and video error:",
+        "audioDeviceProblem": "There is a problem with your audio device",
         "audioOnlyError": "Audio error:",
         "audioTrackError": "Could not create audio track.",
         "calling": "Calling",

react/features/prejoin/middleware.js

 import { SET_AUDIO_MUTED, SET_VIDEO_MUTED } from '../base/media';
 import { MiddlewareRegistry } from '../base/redux';
 import { updateSettings } from '../base/settings';
-import { getLocalVideoTrack, replaceLocalTrack } from '../base/tracks';
+import {
+    getLocalVideoTrack,
+    replaceLocalTrack,
+    TRACK_ADDED,
+    TRACK_NO_DATA_FROM_SOURCE
+} from '../base/tracks';
 
 import { PREJOIN_START_CONFERENCE } from './actionTypes';
-import { setPrejoinPageVisibility } from './actions';
+import {
+    setDeviceStatusOk,
+    setDeviceStatusWarning,
+    setPrejoinPageVisibility
+} from './actions';
 import { isPrejoinPageVisible } from './functions';
 
 declare var APP: Object;
         break;
     }
 
+    case TRACK_ADDED:
+    case TRACK_NO_DATA_FROM_SOURCE: {
+        const state = store.getState();
+
+        if (isPrejoinPageVisible(state)) {
+            const { track: { jitsiTrack: track } } = action;
+            const { deviceStatusType, deviceStatusText } = state['features/prejoin'];
+
+            if (!track.isAudioTrack()) {
+                break;
+            }
+
+            if (track.isReceivingData()) {
+                if (deviceStatusType === 'warning'
+                    && deviceStatusText === 'prejoin.audioDeviceProblem') {
+                    store.dispatch(setDeviceStatusOk('prejoin.lookGood'));
+                }
+            } else if (deviceStatusType === 'ok') {
+                store.dispatch(setDeviceStatusWarning('prejoin.audioDeviceProblem'));
+            }
+        }
+        break;
+    }
+
     }
 
     return next(action);

react/features/prejoin/reducer.js

         }
 
         case SET_DEVICE_STATUS: {
+            const { deviceStatusType, deviceStatusText } = action.value;
+
             return {
                 ...state,
-                deviceStatusText: action.text,
-                deviceStatusType: action.type
+                deviceStatusText,
+                deviceStatusType
             };
         }