magento-test/app/code/Magento/MediaGalleryIntegration/etc/adminhtml/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Ui\Component\Form\Element\DataType\Media\OpenDialogUrl">
        <plugin name="new_media_gallery_open_dialog_url" type="Magento\MediaGalleryIntegration\Plugin\NewMediaGalleryOpenDialogUrl" />
    </type>
    <type name="Magento\Framework\File\Uploader">
        <plugin name="save_asset_image" type="Magento\MediaGalleryIntegration\Plugin\SaveImageInformation"/>
    </type>
    <type name="Magento\MediaGalleryIntegration\Plugin\SaveImageInformation">
        <arguments>
            <argument name="imageExtensions" xsi:type="array">
                <item name="jpg" xsi:type="string">jpg</item>
                <item name="jpeg" xsi:type="string">jpeg</item>
                <item name="gif" xsi:type="string">gif</item>
                <item name="png" xsi:type="string">png</item>
            </argument>
        </arguments>
    </type>
</config>