Updated the test case

1. EDIT cohort via ellipsis menu
2. Saved changes by selecting SAVE drop-down option of SAVE COHORT button

PR checklist

• This PR meets the Acceptance Criteria in the JIRA story
• The JIRA story has been moved to Dev Review
• This PR includes appropriate unit tests
• I have run and tested this change locally
• I have run the E2E tests on ths change against my local UI + API server with yarn test-local
• If this includes a UI change, I have taken screen recordings or screenshots of the new behavior and notified the PO and UX designer
• If this includes an API change, I have updated the appropriate Swagger definitions and notified API consumers
• If this includes a new feature flag, I have created and linked new JIRA tickets to (a) turn on the feature flag and (b) remove it later