Lab 'advanced-load-balancing' -- Fix Retry-Policy glitch (#54)

[ulkeba]

Purpose

Fix issue #54.

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Run 'advanced-load-balancing' lab (reduce AOAI capacity to 2).
• Copy execution loop from 'backend-pool-load-balancing' lab.
• See that retry works for run 3.