Use ::class in test mocks of encryption app

apps/encryption/tests/Command/TestEnableMasterKey.php

apps/encryption/tests/Controller/RecoveryControllerTest.php

apps/encryption/tests/Controller/SettingsControllerTest.php

apps/encryption/tests/Controller/StatusControllerTest.php

apps/encryption/tests/Crypto/CryptTest.php

apps/encryption/tests/Crypto/DecryptAllTest.php

apps/encryption/tests/Crypto/EncryptAllTest.php

apps/encryption/tests/Crypto/EncryptionTest.php

apps/encryption/tests/HookManagerTest.php

apps/encryption/tests/Hooks/UserHooksTest.php

apps/encryption/tests/KeyManagerTest.php

apps/encryption/tests/RecoveryTest.php

apps/encryption/tests/Users/SetupTest.php

apps/encryption/tests/UtilTest.php

...haring/tests/Controller/MountPublicLinkControllerTest.php

apps/federatedfilesharing/tests/TokenHandlerTest.php

apps/files/tests/Command/DeleteOrphanedFilesTest.php

...files_sharing/tests/Command/CleanupRemoteStoragesTest.php

...files_sharing/tests/Controller/ShareAPIControllerTest.php

...rovisioning_api/tests/Controller/GroupsControllerTest.php