Dependency Injection in Drupal Plugin

<?php

namespace Drupal\vishal_default_config\Plugin\Block;

use Drupal\Core\Block\BlockBase;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a 'Default' Block.
 *
 * @Block(
 *   id = "vishal_default_config",
 *   admin_label = @Translation("Default Block Plugin"),
 *   category = @Translation("Custom"),
 * )
 */
class DefaultBlock extends BlockBase implements ContainerFactoryPluginInterface {

  /**
   * Stores the configuration factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * Creates a SystemBrandingBlock instance.
   *
   * @param array $configuration
   *   A configuration array containing information about the plugin instance.
   * @param string $plugin_id
   *   The plugin_id for the plugin instance.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The factory for configuration objects.
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, ConfigFactoryInterface $config_factory) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->configFactory = $config_factory;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('config.factory')
    );
  }

   /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    // var_dump($this->configFactory);
    if($this->configFactory->get('vishal_default_config.settings')->get('vishal_default_config.name')) {

    }

    $conf = [
      'default_name' => 'Default Block Name',
    ];

    //$default_config = $this->configFactory->get('vishal_default_config');

    // $name = $default_config->get('vishal_default_config.name');

    // return [
    //   'vishal_default_config_block_name' => $default_config,
    // ];
  }

  /**
   * {@inheritdoc}
   */
  public function build() {
    return [
      '#markup' => $this->t('Default Config Plugin!'),
    ];
  }

}