istio update to 1.20.4-bb.1

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/istio-controlplane/-/blob/1.20.4-bb.1/CHANGELOG.md

Package MR

big-bang/product/packages/istio-controlplane!217 (merged)

For Issue

Closes big-bang/product/packages/istio-controlplane#147 (closed)

Upgrade Notices

Grafana pods need to be manually deleted and restarted so that it pulls in the new configmap with the correct dashboard json changes.