Update Velero test-values.yaml

Re-evaluate the current test-values.yaml in Big bang

Check for duplicate configurations that are already configured within the values itself and remove them. Add additional testing if needed.

URL: https://repo1.dso.mil/big-bang/product/packages/velero

Default Values URL: https://repo1.dso.mil/big-bang/product/packages/velero/-/raw/main/chart/values.yaml

BB Test Values URL: https://repo1.dso.mil/big-bang/bigbang/-/raw/master/tests/test-values.yaml

Duplicates found in addons.velero for BB Test Values:
credentials.useSecret  =  true