message: ConfigReader-ify SearchBar test.
diff: @@ -21,7 +21,11 @@ import { SearchContextProvider } from '../SearchContext';
  import { SearchBar } from './SearchBar';
  import { configApiRef } from '@backstage/core-plugin-api';
  -import { ApiProvider, ApiRegistry } from '@backstage/core-app-api';
  +import {
  + ApiProvider,
  + ApiRegistry,
  + ConfigReader,
  +} from '@backstage/core-app-api';
  import { searchApiRef } from '../../apis';
  jest.mock('@backstage/core-plugin-api', () => ({
  @@ -37,10 +41,9 @@ describe('SearchBar', () => {
  };
  const query = jest.fn().mockResolvedValue({});
  - const getOptionalString = jest.fn().mockReturnValue('Mock title');
  const apiRegistry = ApiRegistry.from([
  - [configApiRef, { getOptionalString }],
  + [configApiRef, new ConfigReader({ app: { title: 'Mock title' } })],
  [searchApiRef, { query }],
  ]);
  