Remove finalize elevation when updating elevation on the fly

[olsen232]

Don't _finalizeElevation if freezeElevation has not been set.

This means that elevation logic has two distinct operating modes.

Mode one - freezeElevation is false - default:

• updateElevation is called continuously during the movement
• finalizeElevation is not called at the end.

Mode two - freezeElevation is true:

• updateElevation is not called continuoulsy during the movement
• finalizeElevation is called at the end.

Previously, both methods were called in mode one, which lead to issue #3878 if freezeElevation was not set.

Fixes #3878

Launch Checklist

• [x] Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• [x] Briefly describe the changes in this PR.
• [x] Link to related issues.
• [ ] Include before/after visuals or gifs if this PR includes visual changes.
• [x] Write tests for all new functionality.
• [ ] Document any changes to public APIs.
• [ ] Post benchmark scores.
• [x] Add an entry to CHANGELOG.md under the ## main section.