Change filter hook to editor.BlockEdit.
Change filter hook to editor.BlockEdit.

The filter hook name was changed to `editor.BlockEdit` in Gutenberg 3.3.

@see https://github.com/WordPress/gutenberg/blob/41fd116ca1f73a9b5c962c66ea0c4aae338ea35e/docs/reference/deprecated.md#330

ampproject/amp-toolbox-php,ampproject/amp-toolbox-php