In some CI configs we use `JAVA_OPTS` in order to configure the memory of the Optimize JVM, e.g. https://github.com/camunda/camunda-optimize/blob/master/.ci/branch-deployment/deployment.yml#L45 however this variable has no effect on the Optimize JVM anymore as since https://github.com/camunda/camunda-optimize/commit/69a58460cb64cdaffaa27b09c487610f24a7b294 (Optimize 3.3.0) . Since then only the specific `OPTIMIZE_JAVA_OPTS` variable expected in the startup script https://github.com/camunda/camunda-optimize/blob/master/distro/src/optimize-startup.sh#L29 is picked up.
- convert all usages of `JAVA_OPTS` on the Optimize container to `OPTIMIZE_JAVA_OPTS`
- align to docs on which property to use, current docs mention `JAVA_SYSTEM_PROPERTIES` https://docs.camunda.org/optimize/latest/technical-guide/setup/installation/#adjust-optimize-heap-size
- add OPTIMIZE_JAVA_OPTS to the docs on available environment variables https://docs.camunda.org/optimize/latest/technical-guide/setup/installation/#available-environment-variables
- The Migration guide to Optimize 3.3.0 mentions this as a breaking change
- doc changes are backported to 3.3 and latest