fix(settings_buttons): Persist audio/video settings across sessions.

react/features/base/devices/actions.js

 import {
     areDeviceLabelsInitialized,
     getDeviceIdByLabel,
+    getDeviceLabelById,
     getDevicesFromURL,
     setAudioOutputDeviceId
 } from './functions';
     };
 }
 
+/**
+ * Sets the audio input device id and updates the settings
+ * so they are persisted across sessions.
+ *
+ * @param {string} deviceId - The id of the new audio input device.
+ * @returns {Function}
+ */
+export function setAudioInputDeviceAndUpdateSettings(deviceId) {
+    return function(dispatch, getState) {
+        const deviceLabel = getDeviceLabelById(getState(), deviceId, 'audioInput');
+
+        dispatch(setAudioInputDevice(deviceId));
+        dispatch(updateSettings({
+            userSelectedMicDeviceId: deviceId,
+            userSelectedMicDeviceLabel: deviceLabel
+        }));
+    };
+}
+
 /**
  * Updates the output device id.
  *
     };
 }
 
+/**
+ * Sets the video input device id and updates the settings
+ * so they are persisted across sessions.
+ *
+ * @param {string} deviceId - The id of the new video input device.
+ * @returns {Function}
+ */
+export function setVideoInputDeviceAndUpdateSettings(deviceId) {
+    return function(dispatch, getState) {
+        const deviceLabel = getDeviceLabelById(getState(), deviceId, 'videoInput');
+
+        dispatch(setVideoInputDevice(deviceId));
+        dispatch(updateSettings({
+            userSelectedCameraDeviceId: deviceId,
+            userSelectedCameraDeviceLabel: deviceLabel
+        }));
+    };
+}
+
 /**
  * Signals to update the list of known audio and video devices.
  *

react/features/settings/components/web/audio/AudioSettingsPopup.js

 import {
     getAudioInputDeviceData,
     getAudioOutputDeviceData,
-    setAudioInputDevice as setAudioInputDeviceAction,
+    setAudioInputDeviceAndUpdateSettings,
     setAudioOutputDevice as setAudioOutputDeviceAction
 } from '../../../../base/devices';
 import { connect } from '../../../../base/redux';
 
 const mapDispatchToProps = {
     onClose: toggleAudioSettings,
-    setAudioInputDevice: setAudioInputDeviceAction,
+    setAudioInputDevice: setAudioInputDeviceAndUpdateSettings,
     setAudioOutputDevice: setAudioOutputDeviceAction
 };
 

react/features/settings/components/web/video/VideoSettingsPopup.js

 import { toggleVideoSettings } from '../../../actions';
 import {
     getVideoDeviceIds,
-    setVideoInputDevice as setVideoInputDeviceAction
+    setVideoInputDeviceAndUpdateSettings
 } from '../../../../base/devices';
 import { getVideoSettingsVisibility } from '../../../functions';
 import { connect } from '../../../../base/redux';
 
 const mapDispatchToProps = {
     onClose: toggleVideoSettings,
-    setVideoInputDevice: setVideoInputDeviceAction
+    setVideoInputDevice: setVideoInputDeviceAndUpdateSettings
 };
 
 export default connect(mapStateToProps, mapDispatchToProps)(VideoSettingsPopup);