Add check in ecs clint library to ensure only non empty values are added to API request.

[RichaGangwar]

Summary

This PR adds the check in ecs clint library to ensure only non empty values are added to API request.

Implementation details

1. Added empty string check for client.configAccessor.OSFamily() as this is an optional field for one of the users of the ecs client shared library.
2. Added empty string check for client.configAccessor.OSType() as a safety to ensure any future users who have this field as optional would not hit the issue of passing empty value.

Testing

Unit tested
New tests cover the changes: NA

Description for the changelog

Add check in ecs clint library to ensure only non empty values are added to API request.

Does this PR include breaking model changes? If so, Have you added transformation functions?

No

Licensing

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.