istio update to 1.19.6-bb.2

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/istio-controlplane/-/blob/1.19.6-bb.2/CHANGELOG.md

Package MR

big-bang/product/packages/istio-controlplane!205 (merged)

For Issue

Closes big-bang/product/packages/istio-controlplane#120 (closed)

Upgrade Notices

postInstallHook for Istio control plane added container resource limits