feat(virtual-background) persist settings

react/features/virtual-background/reducer.js

 // @flow
 
-import { ReducerRegistry } from '../base/redux';
+import { PersistenceRegistry, ReducerRegistry } from '../base/redux';
 
 import { BACKGROUND_ENABLED, SET_VIRTUAL_BACKGROUND } from './actionTypes';
 
+const STORE_NAME = 'features/virtual-background';
+
+/**
+ * Sets up the persistence of the feature {@code virtual-background}.
+ */
+PersistenceRegistry.register(STORE_NAME, true);
+
 /**
  * Reduces redux actions which activate/deactivate virtual background image, or
  * indicate if the virtual image background is activated/deactivated. The
  * @returns {State} The next redux state that is the result of reducing the
  * specified action.
  */
-ReducerRegistry.register('features/virtual-background', (state = {}, action) => {
+ReducerRegistry.register(STORE_NAME, (state = {}, action) => {
     const { virtualSource, isVirtualBackground, backgroundEffectEnabled } = action;
 
     switch (action.type) {