Fixed Add Channel_test_cases (#22768)

* Fixed Add Channel_test_cases

* fixed more test cases

* fixed lint

e2e-tests/cypress/tests/integration/channels/mark_as_unread/helpers.js

@@ -21,6 +21,7 @@ export function markAsUnreadShouldBeAbsent(postId, prefix = 'post', location = '
         within(() => {
             cy.findByText('Mark as Unread').should('not.exist');
         });
+    cy.get('body').type('esc');
 }
 
 export function switchToChannel(channel) {