ServiceManager in ZF3

You can not use $this->getServiceLocator() in controller any more.

You should add one more class IndexControllerFactory where you will get dependencies and inject it in IndexController

First refactor your config:

'controllers' => [
    'factories' => [
        Controller\IndexController::class => Controller\IndexControllerFactory::class,
    ],
],

Than create IndexControllerFactory.php

<?php

namespace ModuleName\Controller;

use ModuleName\Controller\IndexController;
use Interop\Container\ContainerInterface;
use Zend\ServiceManager\Factory\FactoryInterface;

class IndexControllerFactory implements FactoryInterface
{
    public function __invoke(ContainerInterface $container,$requestedName, array $options = null)
    {
        return new IndexController(
            $container->get(\Doctrine\ORM\EntityManager::class)
        );
    }
}

At the end refactor you IndexController to get dependencies

public function __construct(\Doctrine\ORM\EntityManager $object) {
    $this->objectManager = $object;
    $this->trust = new Trust;
}

You should check official documentation zend-servicemanager and play around a little bit...