Issue #2829680 by tim.plunkett, andypost: BLOCK_LABEL_VISIBLE is defined on the wrong interface

core/lib/Drupal/Core/Block/BlockBase.php

core/lib/Drupal/Core/Block/BlockPluginInterface.php

core/modules/block/src/BlockInterface.php

...odules/block/src/Plugin/migrate/process/BlockSettings.php

core/modules/block/tests/src/Kernel/BlockInterfaceTest.php

core/modules/block/tests/src/Kernel/BlockStorageUnitTest.php

...ules/views/tests/src/Unit/Plugin/Block/ViewsBlockTest.php