webservice: Configure Gitaly client in webservice chart

What does this MR do?

This MR adds the support needed to enable configuring client retries in the Gitaly client of the following components:

• Rails

Here are the MRs that introduced the new config in their respective components:

• Rails: gitlab-org/gitlab!217216 (merged)

Related issues

• gitlab-org/gitlab#584430
• #6238 (closed)

Closes #6238 (closed)

Author checklist

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Required

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• Merge Request Title and Description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• MR has a green pipeline.
• Documentation created/updated.
• Tests added/updated, and test plan for scenarios not covered by automated tests.
• Equivalent MR/issue for omnibus-gitlab opened.

Reviewers checklist

• MR has a green pipeline on https://gitlab.com/gitlab-org/charts/gitlab.
• Consider downstream impact to the Operator, as per evaluating impact from changes to GitLab chart.

Closes #6238 (closed)