21 files declare their use of InstallStorage in Drupal 8

comment.post_update.php in core/modules/comment/comment.post_update.php

Post update functions for the comment module.

ConfigAfterInstallerTestBase.php in core/tests/Drupal/FunctionalTests/Installer/ConfigAfterInstallerTestBase.php

ConfigAfterInstallerTestBase.php in core/modules/system/src/Tests/Installer/ConfigAfterInstallerTestBase.php

ConfigCRUDTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigCRUDTest.php

ConfigImportUITest.php in core/modules/config/tests/src/Functional/ConfigImportUITest.php

ConfigInstallProfileOverrideTest.php in core/modules/config/tests/src/Functional/ConfigInstallProfileOverrideTest.php

ConfigInstallProfileUnmetDependenciesTest.php in core/modules/config/tests/src/Functional/ConfigInstallProfileUnmetDependenciesTest.php

ConfigInstallTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigInstallTest.php

ConfigSchemaTest.php in core/tests/Drupal/KernelTests/Core/Config/ConfigSchemaTest.php

dblog.post_update.php in core/modules/dblog/dblog.post_update.php

Post update functions for the Database Logging module.

DefaultConfigTest.php in core/tests/Drupal/KernelTests/Config/DefaultConfigTest.php

DefaultConfigTest.php in core/tests/Drupal/KernelTests/Core/Config/DefaultConfigTest.php

DemoUmamiProfileTest.php in core/profiles/demo_umami/tests/src/Functional/DemoUmamiProfileTest.php

EntityTypeWithoutViewsDataTest.php in core/modules/datetime_range/tests/src/Kernel/Views/EntityTypeWithoutViewsDataTest.php

FunctionalTestSetupTrait.php in core/lib/Drupal/Core/Test/FunctionalTestSetupTrait.php

MediaDisplayTest.php in core/modules/media/tests/src/FunctionalJavascript/MediaDisplayTest.php

ModuleTestBase.php in core/modules/system/src/Tests/Module/ModuleTestBase.php

ModuleTestBase.php in core/modules/system/tests/src/Functional/Module/ModuleTestBase.php

TestInstallStorage.php in core/modules/config/tests/config_test/src/TestInstallStorage.php

TestViewsTest.php in core/modules/views/tests/src/Kernel/TestViewsTest.php

ThemeSettingsTest.php in core/tests/Drupal/KernelTests/Core/Theme/ThemeSettingsTest.php