Fix `updatedAt` in user documents in firestore

[MehulKChaudhari]

Issue Description

Now we don't update updatedAt field after updating the user details in DB.

Expected Behavior

updatedAt should be updated with latest timestamp every time user details are updated in DB.

Current Behavior

updatedAt is not getting updated after user details are updated in DB. both the createdAt and updatedAt fields have same value.

Screenshots

Reproducibility

• [x] This issue is reproducible
• [ ] This issue is not reproducible

Steps to Reproduce

1. hit API https://api.realdevsquad.com/users and you can see the timestamp not being updated after user details are updated.

Severity/Priority

• [ ] Critical
• [x] High
• [ ] Medium
• [ ] Low

Additional Information

Checklist

• [ ] I have read and followed the project's code of conduct.
• [ ] I have searched for similar issues before creating this one.
• [ ] I have provided all the necessary information to understand and reproduce the issue.
• [ ] I am willing to contribute to the resolution of this issue.