Allow configuration of Fitbit API url

[pvannierop]

Problem

During e2e testing of the Fitbit connector we cannot mock the Fitbit API since the URL is hardcoded.

Solution

This PR will update the chart to make the Fitbit URL configurable.

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching charts/*/values.yaml:

• Is the PR adding a new container? Please reviewer, add it to the models (internal process)
• Is the PR adding a new parameter? Please, ensure it’s documented in the README.md

This is an automatically generated QA checklist based on modified files.

[keyvaann]

LGTM