fixed the return statetment as SampledProperty removeSample is return…

[vipulgusain]

fixed the return statement as SampledProperty removeSample is returning
but this function is not even though the api docs states it should

[cesium-concierge]

Thank you so much for the pull request @vipulgusain! I noticed this is your first pull request and I wanted to say welcome to the Cesium community!

The Pull Request Guidelines is a handy reference for making sure your PR gets accepted quickly, so make sure to skim that.

• ❌ Missing CONTRIBUTORS.md entry.
  • Please add yourself to the contributors file!
• ❌ Missing CLA.
  • Please send in a Contributor License Agreement (CLA) and comment back here to let us know to check this!
• ❔ CHANGES.md was not updated.
  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.
• ❔ Unit tests were not updated.
  • Make sure you've updated tests to reflect your changes, added tests for any new code, and ran the code coverage tool.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.
• Works (or fails gracefully) in IE11.

[vipulgusain]

Contributor License Agreement (CLA) signed and submited

[vipulgusain]

"this is ready"

[hpinkos]

Thanks for the PR @vipulgusain! At a glance this looks good, but I'll have time to do a thorough review and get this merged next week sometime

[hpinkos]

Thanks @vipulgusain! I'll merge as soon as CI passes