Velero Upgrade And Cleanup

General MR

Summary

Several docs were out of date in Velero repo. Some values overrides were not needed as package defaults.

Planning to use the remove-velero-service-override umbrella branch for this MR.

Linked Issue

issue

big-bang/bigbang#3196 (closed)

Upgrade Notices

• Upstream chart bumped to 12.0.0 (major). See upstream release notes and PR #706 for breaking changes.
• Velero app updated to v1.18.0. See Velero v1.18.0 release notes.
• upstream.resources.upgradeJob removed in favor of upstream.upgradeJobResources (fixes bigbang#3196).

Umbrella Branch

remove-velero-service-override