Implements getStartServices on server-side (elastic#55156)

This was already backported, but changes to endpoint app could not be
backported, since endpoint app itself hadn't been backported. Now that
the endpoint app is backported, reapply the endpoint specific changes
from the original commit.

x-pack/plugins/endpoint/server/plugin.test.ts

@@ -3,14 +3,14 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
-import { CoreSetup } from 'kibana/server';
+
 import { EndpointPlugin, EndpointPluginSetupDependencies } from './plugin';
 import { coreMock } from '../../../../src/core/server/mocks';
 import { PluginSetupContract } from '../../features/server';
 
 describe('test endpoint plugin', () => {
   let plugin: EndpointPlugin;
-  let mockCoreSetup: MockedKeys<CoreSetup>;
+  let mockCoreSetup: ReturnType<typeof coreMock.createSetup>;
   let mockedEndpointPluginSetupDependencies: jest.Mocked<EndpointPluginSetupDependencies>;
   let mockedPluginSetupContract: jest.Mocked<PluginSetupContract>;
   beforeEach(() => {