Issue #3087692 by Wim Leers, alexpott: Remove the core key from views configuration

...egator/config/optional/views.view.aggregator_rss_feed.yml

...regator/config/optional/views.view.aggregator_sources.yml

...est_views/test_views/views.view.test_aggregator_items.yml

...lock_test_views/test_views/views.view.test_view_block.yml

...ock_test_views/test_views/views.view.test_view_block2.yml

...ws/test_views/views.view.test_view_block_with_context.yml

...lock_content/config/optional/views.view.block_content.yml

...ests/fixtures/update/views.view.block_content_2976334.yml

...ws/views.view.test_block_content_redirect_destination.yml

.../test_views/views.view.test_block_content_revision_id.yml

...ws/views.view.test_block_content_revision_revision_id.yml

...t_views/test_views/views.view.test_block_content_view.yml

...t_test_views/test_views/views.view.test_field_filters.yml

...tent_test_views/test_views/views.view.test_field_type.yml

.../book_test_views/test_views/views.view.test_book_view.yml

core/modules/comment/config/optional/views.view.comment.yml

...es/comment/config/optional/views.view.comments_recent.yml

...comment_test_views/test_views/views.view.test_comment.yml

...t_views/test_views/views.view.test_comment_field_name.yml

...t_views/test_views/views.view.test_comment_operations.yml