Switched back to component extension

This is for maximum backwards compatibility as React Hook implementation is only supported in WP 5.2 and above.

src/blocks/activity/embed-controls.js

@@ -0,0 +1,33 @@
+/**
+ * WordPress dependencies
+ */
+const { __ } = wp.i18n;
+const {
+	Icon,
+	Button,
+	Toolbar,
+} = wp.components;
+const { BlockControls } = wp.blockEditor;
+
+const EmbedControls = ( props ) => {
+	const {
+		switchBackToURLInput,
+	} = props;
+
+	return (
+		<>
+			<BlockControls>
+				<Toolbar>
+					<Button
+						label={ __( 'Edit URL' ) }
+						onClick={ switchBackToURLInput }
+					>
+						<Icon icon="edit" />
+					</Button>
+				</Toolbar>
+			</BlockControls>
+		</>
+	);
+};
+
+export default EmbedControls;